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Commu ications an Control Unit T e fu ctional part of a Power Transmitter or Pow er Receiver that contr ols the pow er transfer.. Interface Sur face T e flat par t of the sur face of a B

Introduction

The Wireless Power Consortium (WPC) is a global organization dedicated to establishing and promoting standards for wireless power transfer across various applications One of its primary focuses is the wireless charging of low and medium power devices, including mobile phones and tablets The WPC also oversees the Qi logo, which signifies compliance in this application area.

Scope

Current Specification structure (introduced in version )

The Qi Wireless Power Transfer System for Power Class 0 Specification consists of the following documents

 Part 4: Reference Designs (this document)

WPC publications before version 1.2.1 had a different structure, as detailed in Section 1.2.2 Specifically, the Low Power and Medium Power publications were previously presented as separate System Description documents However, starting with version 1.2.1, these descriptions have been integrated into a unified Specification structure Furthermore, the terminology has been updated, with "Low Power" and "Medium Power" now referred to as "Baseline Power Profile" and "Extended Power Profile," respectively, in the current Specification.

Earlier Specification structure (version 1.2.0 and below)

Before release 1.2.1, the Wireless Power Transfer specification comprised the following documents

 System Description, Wireless Power Transfer, Volume I: Low Power, Part 1: Interface Definition

 System Description, Wireless Power Transfer, Volume I: Low Power, Part 2: Performance Requirements

 System Description, Wireless Power Transfer, Volume I: Low Power, Part 3: Compliance Testing

 System Description, Qi Wireless Power Transfer, Volume II: Medium Power.

Main features

 A method of contactless power transfer from a Base Station to a Mobile Device that is based on near field magnetic induction between coils

The Baseline Power Profile enables power transfer of approximately 5 W, while the Extended Power Profile supports up to 15 W, utilizing a suitable Secondary Coil with a typical outer dimension of around 40 mm.

 Operation at frequencies in the 87…205 kHz range

 Support for two methods of placing the Mobile Device on the surface of the Base Station:

 Guided Positioning helps a user to properly place the Mobile Device on the surface of a Base Station that provides power through a single or a few fixed locations of that surface

 Free Positioning enables arbitrary placement of the Mobile Device on the surface of a Base Station that can provide power through any location of that surface

 A simple communications protocol enabling the Mobile Device to take full control of the power transfer

 Considerable design flexibility for integration of the system into a Mobile Device

 Very low stand-by power achievable (implementation dependent)

Conformance and references

Conformance

All provisions in The Qi Wireless Power Transfer System, Power Class 0 Specification are mandatory unless stated otherwise as recommended, optional, note, example, or informative The verbal expression of these provisions adheres to the rules outlined in Annex H of ISO/IEC Directives, Part 2 To ensure clarity, the term “shall” signifies a strict requirement that must be followed to comply with the Specification.

The Qi Wireless Power Transfer System adheres strictly to the Power Class 0 Specification, allowing no deviations The term "should" suggests a recommended course of action among various options, while "may" denotes permissible actions within the specification's limits Additionally, "can" refers to the potential or capability of actions, whether material, physical, or causal.

References

The latest published Specification is applicable for undated references, and the most recent publications from the Wireless Power Consortium (WPC) can be accessed at http://www.wirelesspowerconsortium.com For a comprehensive list of documents included in The Qi Wireless Power Transfer System for Power Class 0 Specification, please refer to Section 1.2.1.

In addition, the following documents are referenced within The Qi Wireless Power Transfer System for Power Class 0 Specification

 Product Registration Procedure Web page (WPC Web site for members, Testing & Registration section)

 Qi Product Registration Manual, Logo Licensee/Manufacturer

 Qi Product Registration Manual, Authorized Test Lab

 Power Receiver Manufacturer Codes, Wireless Power Consortium

 The International System of Units (SI), Bureau International des Poids et Mesures

Definitions

The Active Area refers to the section of the Interface Surface on a Base Station or Mobile Device where a significant magnetic flux enters while the Base Station supplies power to the Mobile Device.

Base Station A device that is able to provide near field inductive power as specified in The Qi

The Wireless Power Transfer System adheres to the Power Class 0 Specification, with Base Stations featuring a logo that visually signifies compliance with the Qi standard.

The minimum set of features applying to Power Transmitters and Power Receivers that can transfer no more than around 5 W of power

The functional part of a Power Transmitter or Power Receiver that controls the power transfer

NOTE With regard to implementation, the Communications and Control Unit may be distributed over multiple subsystems of the Base Station or Mobile Device

Control Point The combination of voltage and current provided at the output of the Power

Receiver, and other parameters that are specific to a particular Power Receiver implementation

Detection Unit The functional part of a Power Transmitter that detects the presence of a Power

Receiver on the Interface Surface

Digital Ping The application of a Power Signal in order to detect and identify a Power Receiver

The minimum set of features applying to Power Transmitters and Power Receivers that can transfer power above 5 W

Free Positioning is a technique that allows users to place a mobile device on the interface surface of a base station without the need for precise alignment between the active areas of both devices.

Foreign Object Any object that is positioned on the Interface Surface of a Base Station, but is not part of a Mobile Device

A process that a Power Transmitter or Power Receiver executes in order to determine if a Foreign Object is present on the Interface Surface

Friendly Metal A part of a Base Station or a Mobile Device in which a Power Transmitter’s magnetic field can generate eddy currents

Guaranteed Power The amount of output power of an appropriate reference Power Receiver that the

Power Transmitters guarantee availability throughout the power transfer phase For those adhering to the Baseline Power Profile, the reference is TPR#1A, as outlined in Part 3: Compliance Testing In contrast, Power Transmitters that follow the Extended Power Profile reference TPR#MP1B, also detailed in Part 3: Compliance Testing.

Guided Positioning is a technique for accurately positioning a mobile device on the interface surface of a base station This method offers users feedback to ensure the active area of the mobile device aligns correctly with the active area of the base station.

The interface surface refers to the flat area of a Base Station that is nearest to the Primary Coil(s) or the flat area of a Mobile Device that is closest to the Secondary Coil.

The Maximum Power refers to the highest level of power that a Power Receiver anticipates delivering at its output during the power transfer phase This value acts as a scaling factor for the Received Power Values reported in the Power Receiver's Received Power Packets.

Mobile Device A device that is able to consume near field inductive power as specified in The Qi

Wireless Power Transfer System, Power Class 0 Specification A Mobile Device carries a logo to visually indicate to a user that the Mobile Device complies with the Specification

The oscillation frequency of the Power Signal

Operating Point The combination of the frequency, duty cycle, and amplitude of the voltage that is applied to the Primary Cell

Packet A data structure for communicating a message from a Power Receiver to a Power

Transmitter or vice versa A Packet consists of a preamble, a header byte, a message, and a checksum A Packet is named after the kind of message that it contains

Potential Power The amount of output power by an appropriate reference Power Receiver that the

Power Transmitters are essential during the power transfer phase For those adhering to the Baseline Power Profile, the reference is TPR#1A, as outlined in Part 3: Compliance Testing In contrast, Power Transmitters that follow the Extended Power Profile reference TPR#MP1B, also detailed in Part 3: Compliance Testing.

The functional part of a Power Transmitter that converts electrical energy to a Power Signal

The power factor is defined as the ratio of active power, measured in watts, to apparent power, which is typically expressed in volt-amperes (VA).

Power Pick-up Unit The functional part of a Power Receiver that converts a Power Signal to electrical energy

The Power Receiver is a crucial subsystem in mobile devices that captures near field inductive power and manages its output availability, as outlined in The Qi Wireless Power Transfer System, Power Class 0 Specification It effectively communicates its power needs to the Power Transmitter to ensure efficient energy transfer.

Power Signal The oscillating magnetic flux that is enclosed by a Primary Cell and possibly a

Boundary conditions are essential for the effective power transfer from a Power Transmitter to a Power Receiver Any violation of these conditions will result in the termination of the power transfer process.

The Power Transmitter is a crucial subsystem of a Base Station that generates near field inductive power and manages its transfer to a Power Receiver, as outlined in The Qi Wireless Power Transfer System, Power Class 0 Specification.

Primary Cell A single Primary Coil or a combination of Primary Coils that are used to provide a sufficiently high magnetic flux through the Active Area

Primary Coil A component of a Power Transmitter that converts electric current to magnetic flux

Received Power refers to the total power dissipated within a Mobile Device due to the magnetic field produced by a Power Transmitter This includes the power accessible at the output for the Mobile Device's use, the power consumed by the Power Receiver for its own functions, and any power lost within the Mobile Device itself.

The quality-factor of Test Power Transmitter #MP1’s Primary Coil at an Operating Frequency of 100 kHz, with a Power Receiver positioned on the Interface Surface and no Foreign Object nearby

Response A sequence of eight consecutive bi-phase modulated bits transmitted by a Power

Transmitter in response to a request from a Power Receiver

Secondary Coil The component of a Power Receiver that converts magnetic flux to electromotive force

Shielding is a crucial component in Power Transmitters and Power Receivers, designed to confine magnetic fields to specific areas In Power Transmitters, it ensures that magnetic fields are directed to the appropriate sections of the Base Station, while in Power Receivers, it limits magnetic fields to designated parts of the Mobile Device.

Specification The set of documents, Parts 1 through 4, that comprise The Qi Wireless Power

Transfer System, Power Class 0 Specification (see Section 1.2.1)

Transmitted Power The total amount of power dissipated outside the Interface Surface of a Base Station, due to the magnetic field generated by the Power Transmitter

WPID A 48-bit number that uniquely identifies a Qi-compliant device.

Acronyms

BSUT Base Station Under Test

MDUT Mobile Device Under Test

UART Universal Asynchronous Receiver Transmitter

Symbols

Cd Capacitance parallel to the Secondary Coil [nF]

Cm Capacitance in the impedance matching network [nF]

퐶P Capacitance in series with the Primary Coil [nF]

CS Capacitance in series with the Secondary Coil [nF]

푑 Duty cycle of the inverter in the Power Transmitter

푑 s Distance between a coil and its Shielding [mm]

푑z Distance between a coil and the Interface Surface [mm]

푓CLK Communications bit rate [kHz]

푓d Resonant detection frequency [kHz]

푓op Operating Frequency [kHz]

푓S Secondary resonance frequency [kHz]

퐽 m Primary Coil current modulation depth [mA]

퐽 o Power Receiver output current [mA]

퐽P Primary Coil current [mA]

Lm Inductance in the impedance matching network [μH]

푀P Primary Coil self inductance [μH]

푀S Secondary Coil self inductance (Mobile Device away from Base Station) [μH]

푀′ S Secondary Coil self inductance (Mobile Device on top of Base Station) [μH]

푃 FO Power loss that results in heating of a Foreign Object [W]

푃PR Total amount of power received through the Interface Surface [W]

푃 PT Total amount of power transmitted through the Interface Surface [W]

푡delay Power Control Hold-off Time [ms]

푡CLK Communications clock period [μs]

푡T Maximum transition time of the communications [μs]

푊o Power Receiver output voltage [V]

Conventions

Cross references

Unless indicated otherwise, cross references to sections include the sub sections contained therein.

Informative text

Informative text is set in italics, unless the complete Section is marked as informative.

Terms in capitals

Terms having a specific meaning in the context of The Qi Wireless Power Transfer System, Power Class 0 Specification are capitalized and defined in Section 1.5.

Units of physical quantities

Physical quantities are expressed in units of the International System of Units.

Decimal separator

The decimal separator is a period

Notation of numbers

Real numbers are expressed using the digits 0 to 9, a decimal point, and may include an exponential component They can also have a positive or negative tolerance indicator When a real number lacks an explicit tolerance indicator, its accuracy is determined to be half of the least significant digit specified.

A specified value of 1.23 with a range of ±0.02 extends from 1.21 to 1.24, while a value of 1.23 +0.01 covers the range from 1.23 to 1.24 Conversely, a value of 1.23 −0.02 spans from 1.21 to 1.23 The exact value of 1.23 is represented within the range of 1.225 to 1.234999 , and when considering a specified value of 1.23 ±10%, the range expands from 1.107 to 1.353.

 Integer numbers in decimal notation are represented using the digits 0 to 9

 Integer numbers in hexadecimal notation are represented using the hexadecimal digits 0 to 9 and A to

F, and are prefixed by “0x” unless explicitly indicated otherwise

 Single bit values are represented using the words ZERO and ONE

Integer numbers in binary notation are represented by sequences of the digits 0 and 1, enclosed in single quotes (e.g., ‘01001’) In a sequence of n bits, the most significant bit (MSB) is the leftmost bit, denoted as bit $ b_{n-1} $, while the least significant bit (LSB) is the rightmost bit, denoted as bit $ b_0 $.

 Numbers that are shown between parentheses are informative.

Bit ordering in a byte

A byte is graphically represented with the most significant bit on the left and the least significant bit on the right, as illustrated in Figure 1, which defines the bit positions within a byte.

Figure 1 Bit positions in a byte

Byte numbering

In a sequence of n bytes, the bytes are labeled as B0, B1, …, Bn–1, where B0 represents the first byte and Bn–1 denotes the last byte The graphical layout of this byte sequence positions B0 in the upper left corner and Bn–1 in the lower right corner.

Multiple-bit fields

Multiple-bit fields in the ID Packet represent unsigned integer values, unless specified otherwise In cases where a multiple-bit field spans several bytes, the most significant bit (MSB) is found in the byte with the lowest address, while the least significant bit (LSB) is located in the byte with the highest address.

NOTE Figure 2 provides an example of a 6-bit field that spans two bytes

Figure 2 Example of multiple-bit field b9 b8 b7 b6 b5 b4 b3 b2 b1 b0

Operators

Exclusive-OR

The symbol ‘’ represents the exclusive-OR operation.

Concatenation

The symbol ‘||’ denotes the concatenation of two bit strings, where the most significant bit (MSB) of the right-hand operand immediately follows the least significant bit (LSB) of the left-hand operand in the resulting string.

Measurement equipment

All measurements shall be performed using equipment that has a resolution of at least one quarter of the precision of the quantity that is to be measured, unless indicated otherwise

EXAMPLE “tstart ms” means that the equipment shall be precise to 0.25 ms

Introduction

The Power Transmitter designs that are defined in this Part 4: Reference Designs, are grouped in two basic types

Type A Power Transmitter designs feature one or more Primary Coils, activating only one at a time with a corresponding Primary Cell These designs incorporate mechanisms for ensuring proper alignment between the Primary Coil and Secondary Coil, allowing for either Guided Positioning or Free Positioning.

Type B Power Transmitters feature multiple Primary Coils, allowing for flexible positioning These transmitters can activate one or more coils from the array to create a Primary Cell at various locations on the Interface Surface.

A Power Transmitter is designed to serve a single Power Receiver at any given moment In contrast, a Base Station can house multiple Power Transmitters, enabling it to support several Mobile Devices at the same time It's important to note that various type B Power Transmitters can utilize shared components, such as the multiplexer and the array of Primary Coils, as detailed in Section 3.3.1.3.

Power Receivers utilizing thin magnetic shielding may suffer from diminished performance when paired with Power Transmitters that include a permanent magnet in or near the Active Area This can lead to limitations in positioning freedom and extended charging times Consequently, Power Transmitter designs A1, A5, and A9 have been deprecated in version 1.2 of the Qi Power Class 0 Specification.

The Power Transmitter designs outlined in part 4 of the Qi Power Class 0 Specification do not incorporate a permanent magnet Any product implementations that feature a permanent magnet within or near the Active Area are deemed non-compliant with this specification.

Baseline Power Profile designs that activate a single Primary Coil at a time

Power Transmitter design A1

Power Transmitter design A1 has been deprecated For further information, see the note in Section 2.1

The A2 Power Transmitter design allows for Free Positioning, as depicted in Figure 3, which showcases its functional block diagram This design comprises three key functional units: the Power Conversion Unit, the Detection Unit, and the Communications and Control Unit.

Figure 3 Functional block diagram of Power Transmitter design A2

The Power Conversion Unit and Detection Unit, as shown in Figure 3, represent the analog components of the design The Power Conversion Unit functions similarly to that of Power Transmitter design A1, utilizing an inverter to transform the DC input into an AC waveform that powers a resonant circuit made up of the Primary Coil and a series capacitor The Primary Coil is strategically mounted on a positioning stage for precise alignment with the Active Area of the Mobile Device, while a voltage sense monitors the voltage across the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 3, represents the digital logic component of the design, closely resembling the Communications and Control Unit found in Power Transmitter design A1.

The Communications and Control Unit decodes messages from the Power Receiver, implements power control algorithms, and regulates the AC waveform's input voltage to manage power transfer It also controls the positioning stage and operates the Detection Unit while interfacing with other Base Station subsystems for user interface functions.

The Detection Unit identifies the approximate location of objects and Power Receivers on the Interface Surface without specifying a particular detection method It is advisable for the Detection Unit to utilize the resonance of the Power Receiver at the detection frequency $ f_d $, as this minimizes the movement of the Primary Coil by avoiding the identification of non-responsive objects An example of a resonant detection method can be found in the Moving Primary Coil based Free Positioning section of Parts 1 and 2: Interface Definitions.

The Power Transmitter design A2 features a single Primary Coil, Shielding, an Interface Surface, and a positioning stage, as outlined in Sections 2.2.2.1.1 to 2.2.2.1.4.

The Primary Coil, designed as a wire-wound type, features litz wire composed of 30 strands, each with a diameter of 0.1 mm Illustrated in Figure 4, the circular-shaped Primary Coil of Power Transmitter design A2 is constructed with multiple layers, all aligned with the same polarity The dimensions of the Primary Coil are detailed in Table 1.

Figure 4 Primary Coil of Power Transmitter design A2 d c d o d i

Table 1 Primary Coil parameters of Power Transmitter design A2

Number of turns per layer 푂 10

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 5 The shielding extends at least 2 mm beyond the outer diameter of the Primary Coil, with a minimum thickness of 0.20 mm, and is positioned beneath the Primary Coil at a maximum distance of $d_s = 0.1$ mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

Figure 5 Primary Coil assembly of Power Transmitter design A2 ds dz

As shown in Figure 5, the distance from the Primary Coil to the Interface Surface of the Base Station is

The top face of the Primary Coil has a thickness of \$d z = 2.5 - 0 + 0.5 \, \text{mm}\$ Additionally, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The positioning stage shall have a resolution of 0.1 mm or better in each of the two orthogonal directions parallel to the Interface Surface

Power Transmitter design A2 utilizes a full-bridge inverter to drive the Primary Coil and a series capacitance, operating at a fixed frequency of 140 kHz The assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 24 \pm 1 \, \mu H$, while the series capacitance is measured at $C_P = 200 \pm 5\% \, nF$ Notably, near resonance, the voltage across the series capacitance can reach up to 50 V peak-to-peak.

The A2 Power Transmitter design utilizes the input voltage to a full-bridge inverter to regulate the power transfer It operates within an input voltage range of 3 to 12 V, where a decrease in input voltage leads to a reduction in power transfer To ensure precise control over the transferred power, the A2 Power Transmitter must adjust the input voltage with a resolution of 50 mV or finer.

When a type A2 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), it shall use an initial input voltage of 8 V

Figure 6 Electrical diagram (outline) of Power Transmitter design A2

The power transfer control will utilize the PID algorithm as outlined in the Power Transfer Control section of Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the full-bridge inverter To ensure precise power control, a type A2 Power Transmitter will measure the amplitude of the Primary Cell voltage, which corresponds to the Primary Coil voltage, with a specified resolution.

5 mV or better Finally, Table 2 provides the values of several parameters that are used in the PID algorithm

Table 2 PID parameters for voltage control

Integral gain 퐿 i 0 mA -1 ms -1

Derivative gain 퐿d 0 mA -1 ms

PID output limit 푁 PID 1,500 N.A

Power Transmitter design A3 enables Free Positioning, and has a design similar to Power Transmitter design A2 See Section 0 for an overview

The primary coil is constructed from litz wire, comprising 11 strands with a diameter of 0.20 mm, and is wound into a single-layer circular shape, as illustrated in Figure 7 Key specifications of the primary coil are outlined in Table 3, providing essential details for its design and implementation.

Figure 7 Primary Coil of Power Transmitter design A3 dc do di

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 8 The shielding must extend at least 1 mm beyond the outer diameter of the Primary Coil, with a minimum thickness of 0.60 mm, and should be positioned below the Primary Coil at a maximum distance of $d_s = 0.4$ mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

The top face of the Primary Coil has a thickness of \$d z = 2.5 - 0 + 0.5 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The positioning stage shall have a resolution of 0.1 mm or better in each of the two orthogonal directions parallel to the Interface Surface

The Power Transmitter design A3, illustrated in Figure 9, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Operating within a frequency range of 105 kHz to 140 kHz, the combination of the Primary Coil and Shielding exhibits a self-inductance of \$M_P = 16.5 \pm 10\% \, \mu H\$ Additionally, the series capacitance is measured at \$C_P = 180 \pm 5\% \, nF\$.

NOTE Near resonance, the voltage developed across the series capacitance can reach levels up to 100 V pk-pk

When a type A3 Power Transmitter initially applies a Power Signal, it should use a starting input voltage of 6 V and an Operating Frequency of 140 kHz If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it must remove the Power Signal as outlined in the Interface Definitions The Power Transmitter can reapply the Power Signal multiple times at consecutively lower Operating Frequencies within the specified range until it receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the full-bridge inverter To ensure precise power control, a type A3 Power Transmitter will measure the amplitude of the Primary Cell voltage, which corresponds to the Primary Coil voltage, with a resolution of 5 mV or better Additionally, Table 4 lists various parameters utilized in the PID algorithm.

Integral gain 퐿i 0 mA -1 ms -1

Derivative gain 퐿 d 0 mA -1 ms

PID output limit 푁PID 1,500 N.A

The A4 Power Transmitter design allows for flexible positioning, as depicted in Figure 10, which shows its functional block diagram This design comprises two primary components: the Power Conversion Unit and the Communications and Control Unit.

The Power Conversion Unit and Detection Unit, as shown in Figure 10, represent the analog components of the design The inverter transforms the DC input into an AC waveform that energizes a resonant circuit, which includes a chosen Primary Coil and a series capacitor The selected Primary Coil is one of two partially overlapping coils, chosen based on the Power Receiver's position relative to them The Power Transmitter initiates communication with the Power Receiver using either Primary Coil Additionally, the voltage sense function monitors the voltage and current of the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 10, serves as the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block to connect the correct Primary Coil, and implements power control algorithms to manage the AC waveform input voltage for effective power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A4 includes two Primary Coils as defined in Section 2.2.4.1.1, Shielding as defined in Section 2.2.4.1.2, and an Interface Surface as defined in Section 2.2.4.1.3

The Primary Coils are constructed from litz wire, featuring 115 strands with a diameter of 0.08 mm As illustrated in Figure 11, these coils have a racetrack-like shape and are designed with a single layer The dimensions of a Primary Coil are detailed in Table 5.

Figure 11 Primary Coil of Power Transmitter design A4

Outer length 푑ol 70 ±0.5 mm

Inner length 푑il 15 ±0.5 mm

Outer width 푑 ow 59 ±0.5 mm

Inner width 푑iw 4 ±0.5 mm

Number of turns per layer 푂 23.5

The Power Transmitter design A4 features two Primary Coils positioned within a Shielding block, aligned along their long axes with a center displacement of $d_h = 41 \pm 0.5$ mm Refer to Figure 12 for a visual representation.

Figure 12 Dual Primary Coils (top view)

Soft-magnetic material is utilized to shield the Base Station from the magnetic field generated by the Primary Coils, as illustrated in Figure 13 The Shielding block is precisely aligned with the top face of the Primary Coils, encasing them on all sides except the top Additionally, the Shielding extends at least 2.5 mm beyond the outer edge of the Primary Coils and has a minimum thickness of 5 mm This version of Part 4: Reference Designs restricts the Shielding materials to a specified list.

 Mn-Zn-Ferrite Dust Core — any supplier

Figure 13 Primary Coil assembly of Power Transmitter design A4

The measurement of \$d z\$ is 2.0 ± 0.5 mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

2.2.4.1.4 Separation between multiple Power transmitters

In a Base Station that contains multiple type A4 Power Transmitters, the Primary Coil assemblies of any pair of Power Transmitter shall not overlap

NOTE The two Primary Coils within an assembly do overlap as defined in Section 2.2.4.1.1

Power Transmitter design A4, illustrated in Figure 14, employs a full-bridge inverter to energize the Primary Coils along with a series capacitance Furthermore, this design incorporates coil selection switches SWu and SWl to ensure that only one Primary Coil is connected to the inverter at any given time.

The Primary Coils in the assembly, operating within a frequency range of 110 to 180 kHz, exhibit a self-inductance of $M_P = 24 \pm 0.5 \, \mu H$ The series capacitance is measured at $C_P = 100 \pm 5\% \, nF$, and the input voltage supplied to the full-bridge inverter ranges from 5 to 11 V.

The A4 Power Transmitter design utilizes the operating frequency and input voltage of the full-bridge inverter to regulate power transfer To ensure precise power adjustment, it is essential for the A4 Power Transmitter to control the frequency with a resolution of 0.5 kHz and the input voltage with a resolution of 50 mV or finer.

When a type A4 Power Transmitter first applies a Power Signal (Digital Ping; see Part 4: Reference Designs), the Power Transmitter shall use an Operating Frequency of 130 kHz, and an input voltage of 8 V

If the Power Transmitter fails to receive a Signal Strength Packet from the Power Receiver, it will eliminate the Power Signal as outlined in Part 4: Reference Designs The Power Transmitter can reapply the Power Signal several times at an Operating Frequency of 130 kHz, utilizing progressively higher input voltages within the specified range, until it successfully receives a Signal Strength Packet with a suitable Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies both the Operating Frequency and the input voltage to the full-bridge inverter It is advisable to primarily manage power control through adjustments to the Operating Frequency, with voltage modifications reserved for the limits of this frequency range To ensure precise power control, a type A4 Power Transmitter must measure the amplitude of the Primary Coil current with a resolution of 5 mA or better Additionally, Table 6 and Table 7 present various parameters essential for the PID algorithm.

Table 6 PID parameters for Operating Frequency control

Power Transmitter design A5 has been deprecated For further information, see the note in Section 2.1

Figure 15 illustrates the functional block diagram of this design, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Power Conversion Unit, illustrated in Figure 15, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The Primary Coil is selected from a linear array of partially overlapping coils, depending on the Power Receiver's position The selection process involves the Power Transmitter attempting to communicate with the Power Receiver through any of the available Primary Coils, although if there is only one coil, the selection is straightforward Additionally, a current sensor monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 15, is the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block for the correct Primary Coil connection, and implements power control algorithms and protocols to regulate the AC waveform frequency for power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A6 includes one or more Primary Coils as defined in Section 2.2.6.1.1, Shielding as defined in Section 2.2.6.1.2, an Interface Surface as defined in Section 2.2.6.1.3

The Primary Coil is constructed from wire-wound type 2 litz wire, specifically no 17 AWG (1.15 mm diameter) with 105 strands of no 40 AWG (0.08 mm diameter) It features a rectangular shape and is designed with a single layer, as illustrated in Figure 16 The dimensions of the Primary Coil are detailed in Table 8.

Figure 16 Primary Coil of Power Transmitter design A6 dil dol dow diw

Outer length 푑 ol 53.2 ±0.5 mm

Inner length 푑il 27.5 ±0.5 mm

Outer width 푑 ow 45.2 ±0.5 mm

Inner width 푑iw 19.5 ±0.5 mm

Number of turns per layer 푂 12 turns

The Power Transmitter design A6 features a minimum of one Primary Coil, with odd-numbered coils arranged parallel to each other, maintaining a center-to-center displacement of \$d_{oo} = 49.2 \pm 4 \, \text{mm}\$ In contrast, even-numbered coils are positioned orthogonally to the odd-numbered coils, with a center-to-center displacement of \$d_{oe} = 24.6 \pm 2 \, \text{mm}\$ Refer to Figure 17 for a visual representation.

Figure 17 Primary Coils of Power Transmitter design A6

Soft-magnetic material serves to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 18 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.5 mm, and should be positioned beneath the Primary Coil at a maximum distance of 1.0 mm This section of Part 4: Reference Designs restricts the shielding materials to a specified list.

Figure 18 Primary Coil assembly of Power Transmitter design A6 d s dz

The distance across the top face of the Primary Coil is given by \$d_z = 2 - 0.25 + 0.5\$ mm For a single Primary Coil, the distance from the coil to the Interface Surface of the Base Station is \$d_z = 3 - 0.25 + 0.5\$ mm Furthermore, the Interface Surface of the Base Station extends at least 5 mm beyond the outer dimensions of the Primary Coils.

If the Base Station contains multiple type A6 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 49.2 ±4 mm

The Power Transmitter design A6 utilizes a half-bridge inverter to operate an individual Primary Coil along with a series capacitance The assembly of Primary Coils and Shielding exhibits a self-inductance of $M_P = 11.5 \pm 10\% \, \mu H$ for coils nearest to the Interface Surface, and $M_P = 12.5 \pm 10\% \, \mu H$ for those furthest away Additionally, the series capacitance values are $C_P = 0.147 \pm 5\% \, \mu F$ for the closest coils and $C_P = 0.136 \pm 5\% \, \mu F$ for the more distant coils The input voltage supplied to the half-bridge inverter is also specified.

NOTE Near resonance, the voltage developed across the series capacitance can reach levels exceeding 100 V pk-pk

The A6 Power Transmitter design regulates power transfer by adjusting the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 115 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at 205 kHz Increasing the Operating Frequency or decreasing the duty cycle leads to reduced power transfer To ensure precise control over the power output, the A6 Power Transmitter must adjust the Operating Frequency with high resolution.

 0.01 × 푓 op − 0.7 kHz, for fop in the 115…175 kHz range;

The power signal must be controlled by a type A6 Power Transmitter, ensuring a duty cycle resolution of 0.1% or better This applies to the frequency range of 175 to 205 kHz, where the relationship is defined as 0.015 × \$f_{op} - 1.58\$ kHz.

When a type A6 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), it shall use an initial Operating Frequency of 175 kHz (and a duty cycle of 50%)

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the Operating Frequency or duty cycle To ensure precise power control, a type A6 Power Transmitter must measure the amplitude of the Primary Cell current, which is equivalent to the Primary Coil current, with a resolution of 7 mA or better Additionally, Tables 9, 10, and 11 present various parameter values utilized in the PID algorithm.

Integral gain 퐿i 0.05 mA -1 ms -1

Table 10 Operating Frequency dependent scaling factor

Frequency Range [kHz] Scaling Factor 푺 v [Hz]

Table 11 PID parameters for duty cycle control

Integral gain 퐿 i 0.05 mA -1 ms -1

Power Transmitter design A7 enables Free Positioning, and has a design similar to Power Transmitter design A2 See Section 0 for an overview

The Primary Coil is a wire-wound type made of litz wire, featuring 100 strands with a diameter of 0.08 mm It has a circular shape and consists of a single layer, as illustrated in Figure 20 The dimensions of the Primary Coil are detailed in Table 12.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 21 The shielding must extend to the edges of the Primary Coil, have a minimum thickness of 0.60 mm, and be positioned beneath the Primary Coil at a maximum distance of 0.5 mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

The measurement of the top face of the Primary Coil is \$d z = 3.0 \pm 0.5 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The positioning stage shall have a resolution of 0.1mm or better in each of the two orthogonal directions parallel to the Interface Surface

The Power Transmitter design A7, illustrated in Figure 22, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Operating within a frequency range of 105 kHz to 140 kHz, the combination of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 13.6 \pm 10\% \, \mu H$, while the series capacitance is measured at $C_P = 180 \pm 5\% \, nF$.

When a type A7 Power Transmitter initially applies a Power Signal, it should use an input voltage of 6.5 V and an Operating Frequency of 140 kHz If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it will remove the Power Signal as outlined in the Interface Definitions The Power Transmitter may then reapply the Power Signal at consecutively lower Operating Frequencies within the specified range until it receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the full-bridge inverter To ensure precise power control, a type A7 Power Transmitter will measure the amplitude of the Primary Cell voltage, which corresponds to the Primary Coil voltage, with a resolution of 5 mV or better Additionally, Table 13 lists various parameters utilized in the PID algorithm.

The A8 Power Transmitter design allows for flexible positioning, as depicted in Figure 23, which shows its functional block diagram This design features two primary components: a Power Conversion Unit and a Communications and Control Unit.

The Power Conversion Unit, illustrated on the right side of Figure 23, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, voltage and current sensing monitors are employed to track the voltage and current of the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 23, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the input power and frequency of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A8 includes one Primary Coil as defined in Section 2.2.8.1.1, Shielding as defined in Section 2.2.8.1.2, and an Interface Surface as defined in Section 2.2.8.1.3

The Primary Coil features a wire-wound design made from litz wire, comprising 115 strands with a diameter of 0.08 mm As illustrated in Figure 24, the coil has a racetrack-like shape and is constructed in a single layer The dimensions of the Primary Coil are detailed in Table 14.

Outer width 푑 ow 59 ±0.5 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field generated by the Primary Coil, as illustrated in Figure 25 The Shielding block is precisely aligned with the top face of the Primary Coil, encasing it on all sides except the top Additionally, the Shielding extends at least 2.5 mm beyond the outer edge of the Primary Coil and has a minimum thickness of 3.1 mm This version of Part 4: Reference Designs restricts the Shielding materials to a specified list.

 Mn-Zn-Ferrite Dust Core— any supplier

If the Base Station contains multiple type A8 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 70 mm.

The Power Transmitter design A8, illustrated in Figure 26, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Operating within a frequency range of 110 to 180 kHz, the combination of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 24 \pm 0.5 \, \mu H$.

퐶P= 100 ±5% nF The input voltage to the full-bridge inverter is 5 ±0.5 …11 ±0.5 V

The A8 Power Transmitter design utilizes the operating frequency and input voltage of the full-bridge inverter to regulate power transfer To ensure precise power adjustment, the A8 Power Transmitter must control the frequency with a resolution of 0.5 kHz and the input voltage with a resolution of 50 mV or better.

When a type A8 Power Transmitter initially sends a Power Signal (Digital Ping), it operates at a frequency of 130 kHz and requires a specific input voltage.

If the Power Transmitter fails to receive a Signal Strength Packet from the Power Receiver, it will eliminate the Power Signal as outlined in the Interface Definitions The Power Transmitter can reapply the Power Signal at an Operating Frequency of 130 kHz, using progressively higher input voltages, until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies both the Operating Frequency and the input voltage to the full-bridge inverter It is advisable to primarily adjust the Operating Frequency for power control, with voltage adjustments reserved for the limits of the Operating Frequency range To ensure precise power control, a type A8 Power Transmitter must measure the amplitude of the Primary Coil current with a resolution of 5 mA or better Additionally, Table 15 and Table 16 present various parameters essential for the PID algorithm.

Power Transmitter design A9 has been deprecated For further information, see the note in Section 2.1.

The A10 Power Transmitter design facilitates Guided Positioning, as depicted in Figure 27, which showcases its functional block diagram This design comprises two primary components: the Power Conversion Unit and the Communications and Control Unit.

The Power Conversion Unit, illustrated in Figure 27, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, a current sense device monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 27, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the AC waveform frequency to manage power transfer Additionally, this unit connects with other Base Station subsystems for user interface functionalities.

The Power Transmitter design A10 features a single Primary Coil, Shielding, an Interface Surface, and an alignment aid, as outlined in Sections 2.2.10.1.1 to 2.2.10.1.4.

The primary coil is constructed from a wire-wound type, utilizing no 17 AWG (1.15 mm diameter) type 2 litz wire, comprising 105 strands of no 40 AWG (0.08 mm diameter) or equivalent Characterized by a circular shape, the primary coil features multiple layers, all stacked with the same polarity, as illustrated in Figure 28 Key dimensions of the primary coil are outlined in Table 17, providing a comprehensive overview of its structural specifications.

As shown in Figure 29 the distance from the Primary Coil to the Interface Surface of the Base Station is

The Primary Coil features a dimensional tolerance of Δz = 2 - 0.25 + 0.5 mm across its top face, ensuring precise alignment Furthermore, the Interface Surface of the Base Station protrudes at least 5 mm beyond the outer diameter of the Primary Coil, providing a secure and stable connection.

The distance from the Primary Coil to the Interface Surface indicates that the tilt angle between them should not exceed 1.0° For non-flat Interface Surfaces, this distance suggests a minimum radius of curvature of 317 mm, centered on the Primary Coil.

The user manual of the Base Station containing a type A10 Power Transmitter shall have information about the location of its Active Area(s)

For the best user experience, it is recommended to employ at least one user feedback mechanism during Mobile Device positioning to help alignment

NOTE Examples of Base Station alignment aids to assist the user positioning of the Mobile Device include:

 A marked Interface Surface to indicate the location of the Active Area(s)—e.g by means of the logo or other visual marking, lighting, etc

 A visual feedback display—e.g by means of illuminating an LED to indicate proper alignment

 An audible or haptic feedback mechanism

If the Base Station contains multiple type A10 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 50 mm

The Power Transmitter design A10, illustrated in Figure 30, employs a half-bridge inverter to drive the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly comprising the Primary Coil, Shielding, and magnet exhibits a self-inductance of $M_P = 24 \pm 10\% \, \mu H$ Additionally, the series capacitance is $C_P = 100 \pm 5\% \, nF$, and the input voltage to the half-bridge inverter is maintained at $19 \pm 1 \, V$.

 0.01 × 푓 op − 0.7 kHz, for fop in the 110…175 kHz range;

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ within the 175 to 205 kHz range or better Additionally, a type A10 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the Operating Frequency or duty cycle To ensure precise power control, a type A10 Power Transmitter must measure the amplitude of the Primary Cell current, which is equivalent to the Primary Coil current, with a resolution of 7 mA or better Additionally, Tables 18, 19, and 20 present various parameter values utilized in the PID algorithm.

Frequency Range [kHz] Scaling Factor 푺v [Hz]

The A11 Power Transmitter design facilitates Guided Positioning, as depicted in Figure 31, which showcases its functional block diagram This design comprises two primary components: a Power Conversion Unit and a Communications and Control Unit.

The Communications and Control Unit, depicted on the left side of Figure 31, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms and protocols, and regulates the frequency of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

The Primary Coil is constructed from wire-wound type 2 litz wire, featuring 105 strands of no 40 AWG, with a total diameter of 1.15 mm (17 AWG) It has a circular shape and can be made with one or two layers, as illustrated in Figure 32 For detailed dimensions, refer to Table 21.

Number of turns per layer 푂 10 (5 bifilar turns)

As shown in Figure 33 the distance from the Primary Coil to the Interface Surface of the Base Station is

The top face of the Primary Coil has a height of \$d z = 2 - 0.25 + 0.5 \, \text{mm}\$ Additionally, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The distance from the Primary Coil to the Interface Surface indicates that the maximum tilt angle between the Primary Coil and a flat Interface Surface is 1.0° For non-flat Interface Surfaces, this distance suggests a minimum radius of curvature of 317 mm, centered on the Primary Coil.

The Power Transmitter design A11, illustrated in Figure 34, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance The assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 6.3 \pm 10\% \, \mu H$ within the specified operating frequency range Additionally, the series capacitance is valued at $C_P = 0.4 \pm 5\% \, \mu F$, with an input voltage to the full-bridge inverter set at $5 \pm 5\% \, V$.

The A11 Power Transmitter design regulates power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 110 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at an Operating Frequency of 205 kHz An increase in Operating Frequency or a decrease in duty cycle leads to reduced power transfer To ensure precise control over the power transferred, the A11 Power Transmitter must adjust the Operating Frequency with a high resolution.

 0.01 × 푓op− 0.7 kHz, for fop in the 110…175 kHz range;

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ within the range of 175 to 205 kHz or better Additionally, a type A11 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ in this algorithm signifies the Operating Frequency or duty cycle To ensure precise power control, a type A11 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, the values of various parameters used in the PID algorithm are detailed in Tables 22, 23, and 24.

Figure 35 illustrates the functional block diagram of Power Transmitter design A12, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Communications and Control Unit, depicted on the left side of Figure 35, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the frequency of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A12 includes a single Primary Coil as defined in Section 2.2.12.1.1, Shielding as defined in Section 2.2.12.1.2, and an Interface Surface as defined in Section 2.2.12.1.3

The Primary Coil features a wire-wound design made from litz wire, comprising 115 strands with a diameter of 0.08 mm As illustrated in Figure 36, it has a racetrack-like shape and is constructed in a single layer The dimensions of the Primary Coil are detailed in Table 25.

Outer length 푑 ol 70 ±0.5 mm

Inner length 푑 il 15 ±0.5 mm

Outer width 푑ow 59 ±0.5 mm

Number of turns per layer 푂 12 (bifilar turns)

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 37 The shielding extends at least 2.5 mm beyond the outer edge of the Primary Coil and has a minimum thickness of 0.5 mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

The measurement of \$d z\$ is \$2.0 \pm 0.5\$ mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The Power Transmitter design A12, illustrated in Figure 38, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 7 \pm 10\% \, \mu H$ The series capacitance is valued at $C_P = 400 \pm 5\% \, nF$, and the input voltage to the full-bridge inverter is set at $5 \pm 0.5 \, V$.

The A12 Power Transmitter design utilizes the operating frequency and duty cycle of a full-bridge inverter to regulate power transfer The operating frequency ranges from 110 kHz to 205 kHz, with a duty cycle of 50%, while the duty cycle can vary from 2% to 50% at 205 kHz A higher operating frequency combined with a lower duty cycle results in reduced power transfer To ensure precise power adjustment, the A12 Power Transmitter must control the frequency with a resolution of 0.5 kHz or better and the duty cycle with a resolution of 0.1% or better.

When a type A12 Power Transmitter initially applies a Power Signal at a frequency of 175 kHz and a duty cycle of 50%, it will remove the Power Signal if it does not receive a Signal Strength Packet from the Power Receiver The Power Transmitter can reapply the Power Signal at consecutively lower Operating Frequencies until it successfully receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ in this algorithm signifies the Operating Frequency or duty cycle To ensure precise power control, a type A12 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 5 mA or better Additionally, Table 26 and Table 27 present various parameter values essential for the PID algorithm.

The Power Conversion Unit, depicted in Figure 39, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The selected Primary Coil is part of a linear array of partially overlapping coils, tailored to the Power Receiver's position The selection process involves the Power Transmitter attempting to communicate with the Power Receiver through any of the available Primary Coils, although if there is only one coil in the array, the selection is straightforward Additionally, a current sensor monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 39, serves as the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block to connect the correct Primary Coil, and implements power control algorithms and protocols Additionally, it regulates the frequency of the AC waveform to manage power transfer and interfaces with other Base Station subsystems for user interface functionalities.

The Primary Coil is constructed from wire-wound type 2 litz wire, specifically no 17 AWG (1.15 mm diameter) with 105 strands of no 40 AWG (0.08 mm diameter) It features a rectangular shape and is designed with a single layer, as illustrated in Figure 40 The dimensions of the Primary Coil are detailed in Table 28.

Outer length 푑ol 53.2 ±0.5 mm

The design of Power Transmitter A13 features a minimum of one Primary Coil, with odd-numbered coils arranged parallel to each other, maintaining a center-to-center displacement of \$d_{oo} = 49.2 \pm 4 \, \text{mm}\$ In contrast, even-numbered coils are positioned orthogonally to the odd-numbered coils, with a center-to-center displacement of \$d_{oe} = 24.6 \pm 2 \, \text{mm}\$ Refer to Figure 41 for a visual representation.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 42 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.5 mm, and should be positioned beneath the Primary Coil at a maximum distance of 1.0 mm This section of Part 4: Reference Designs specifies that the shielding material must be selected from a designated list of options.

The distance across the top face of the Primary Coil is measured at \$d z = 3 \pm 1 \text{ mm}\$ For a single Primary Coil, the distance to the Interface Surface of the Base Station is \$d z = 4.5 \pm 1 \text{ mm}\$ Furthermore, the Interface Surface of the Base Station extends at least 5 mm beyond the outer dimensions of the Primary Coils.

The Power Transmitter design A13, illustrated in Figure 43, employs a full-bridge inverter to operate an individual Primary Coil along with a series capacitance The assembly of Primary Coils and Shielding exhibits a self-inductance of $M_P = 11.5 \pm 10\% \, \mu H$ for coils nearest to the Interface Surface, and $M_P = 12.5 \pm 10\% \, \mu H$ for those furthest away The inductance values $M_1$ and $M_2$ are $1 \pm 20\% \, \mu H$ Additionally, the total series capacitance is calculated as $1/C_{ser1} + 1/C_{ser2} = 1/200 \pm 10\% \, 1/nF$, while the parallel capacitance is $C_{par} = 400 \pm 10\% \, nF$.

The Power Transmitter design A13 regulates power transfer by utilizing the inverter's input voltage, which ranges from 1 to 12 V with a resolution of 10 mV or better It operates at a frequency of \$f_{op} = 105 \ldots 115 \text{ kHz}\$ and maintains a duty cycle of 50%.

The A13 Power Transmitter initiates a Power Signal with an initial voltage of 3.5 ±0.5 V for the bottom Primary Coil and 3.0 ±0.5 V for the top Primary Coil, operating at a recommended frequency of 110 kHz.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the inverter To ensure precise power control, a type A13 Power Transmitter will measure the amplitude of the Primary Cell current, matching the Primary Coil current, with a resolution of 7 mA or better Additionally, Table 29 lists various parameters essential for the PID algorithm.

The Power Conversion Unit, illustrated in Figure 44, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The selected Primary Coil is part of a linear array of partially overlapping coils, tailored to the Power Receiver's position The Power Transmitter initiates communication with the Power Receiver by selecting from the available Primary Coils, with the process being straightforward if only one coil is present Additionally, a current sensor monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 44, serves as the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block for the correct Primary Coil connection, implements power control algorithms and protocols, and regulates the AC waveform frequency to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

The Primary Coil features a wire-wound design made from litz wire, comprising 115 strands with a diameter of 0.08 mm Its racetrack-like shape, depicted in Figure 45, consists of a single layer For detailed specifications, refer to Table 30, which outlines the dimensions of the Primary Coil.

Outer width 푑ow 59 ±0.5 mm

The Power Transmitter design A14 features two Primary Coils positioned within a Shielding block, aligned along their long axes with a center displacement of $d_h = 38 \pm 0.5$ mm.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field generated by the Primary Coil, as illustrated in Figure 47 The Shielding block is precisely aligned with the top face of the Primary Coils, encasing them on all sides except the top Additionally, the Shielding extends at least 2.5 mm beyond the outer edge of the Primary Coils and has a minimum thickness of 4.7 mm This version of Part 4: Reference Designs specifies that the Shielding composition must be selected from a designated list of materials.

 Mn-Zn-Ferrite Dust Core – any supplier

The measurement of \$d z\$ is \$2.0 \pm 0.5\$ mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer edges of the Primary Coils.

Power Transmitter design A14, illustrated in Figure 48, employs a full-bridge inverter to energize the Primary Coils along with a series capacitance Additionally, this design incorporates coil selection switches SWu and SWl to ensure that only one Primary Coil is connected to the inverter at any given time.

The assembly of Primary Coils and Shielding exhibits a self-inductance of \$M_P = 24 \pm 1.0 \, \mu H\$ within the specified operating frequency range The series capacitance is \$C_P = 100 \pm 5\% \, nF\$, and the input voltage to the full-bridge inverter is \$12 \pm 10\% \, V\$.

NOTE Near resonance, the voltage developed across the series capacitance can reach levels up to 100 Vpk-pk

The A14 Power Transmitter design utilizes the Operating Frequency and duty cycle of a full-bridge inverter to regulate power transfer The full-bridge inverter operates within a frequency range of 110 to 205 kHz, with a duty cycle of 50%, and a duty cycle range of 2% to 50% at the same frequency Higher Operating Frequencies combined with lower duty cycles lead to reduced power transfer To ensure precise power adjustment, the A14 Power Transmitter must control frequency with a resolution of 0.5 kHz or better, and the duty cycle of the Power Signal with a resolution of 0.1% or better.

When the type A14 Power Transmitter initially applies a Power Signal at a frequency of 142 kHz and a duty cycle of 50%, it will remove the Power Signal if it does not receive a Signal Strength Packet from the Power Receiver The Power Transmitter can reapply the Power Signal multiple times at consecutively lower Operating Frequencies until it successfully receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Sections 1 and 2: Interface Definitions The controlled variable, denoted as $ w(i) $, represents the Operating Frequency or duty cycle To ensure precise power control, a type A14 Power Transmitter must measure the amplitude of the Primary Cell current, which is equivalent to the Primary Coil current, with a resolution of 5 mA or better Additionally, Tables 31 and 32 present various parameter values utilized in the PID algorithm.

Figure 49 illustrates the functional block diagram of Power Transmitter design A15, which consists of three major functional units, namely a Power Conversion Unit, a Detection Unit, and a Communications and Control Unit

The Power Conversion Unit and Detection Unit, as illustrated in Figure 49, represent the analog components of the design The inverter is responsible for transforming the DC input into an AC waveform that powers a resonant circuit, which includes the Primary Coil and a series capacitor Additionally, the voltage sense component monitors the voltage across the Primary Coil.

The Detection Unit identifies the approximate location of objects and Power Receivers on the Interface Surface without specifying a particular detection method It is advisable for the Detection Unit to utilize resonance in the Power Receiver at the detection frequency $ f_d $, as outlined in the Power Receiver Design Requirements section of Parts 1 and 2: Interface Definitions This method reduces the movement of the Secondary Coil, since the Power Transmitter does not need to notify users about non-responsive objects at this resonant frequency An example of a resonant detection method can be found in Parts 1 and 2: Interface Definitions.

The Primary Coil features a wire-wound design made from litz wire, comprising 100 strands with a diameter of 0.08 mm Illustrated in Figure 50, the coil is circular and constructed in a single layer For detailed specifications, refer to Table 33, which outlines the dimensions of the Primary Coil.

NOTE This Primary Coil is identical to the Primary Coil of Power Transmitter Design A7

The alignment aid consists of a visual, audible or tactile indication, which helps a user to guide a Power Receiver into the Active Area of the Interface Surface by giving directional feedback

NOTE An example is a LED indicator, which shows at least two directions.

The Power Transmitter design A15, illustrated in Figure 52, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Operating within a frequency range of 105 kHz to 140 kHz, the combination of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 13.6 \pm 10\% \, \mu H$ Additionally, the series capacitance is measured at $C_P = 180 \pm 5\% \, nF$.

The A15 Power Transmitter design utilizes input voltage to regulate power transfer through a full-bridge inverter It operates within an input voltage range of 3 to 12 V, where lower voltages correspond to reduced power transfer To ensure precise control over the transferred power, the A15 Power Transmitter must adjust the input voltage with a resolution of 50 mV or finer.

When the type A15 Power Transmitter initially applies a Power Signal, it should use an input voltage of 5.7 V and an Operating Frequency of 140 kHz If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it will remove the Power Signal as outlined in the Interface Definitions The Power Transmitter may then reapply the Power Signal at consecutively lower Operating Frequencies within the specified range until it receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Sections 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the input voltage to the full-bridge inverter To ensure precise power control, a type A15 Power Transmitter will measure the amplitude of the Primary Cell voltage, which corresponds to the Primary Coil voltage, with a resolution of 5 mV or better Additionally, Table 34 lists various parameters utilized in the PID algorithm.

The WPC has observed that Power Transmitters designed with A 16 technology are underperforming in Foreign Object Detection Consequently, they have decided to phase out the registration of new Base Station products utilizing this design The specific cut-off date for this phase-out has yet to be determined.

The design of the Power Transmitter A16 features a single Primary Coil, shielding, an Interface Surface, and an alignment aid, as detailed in Sections 2.2.16.1.1 through 2.2.16.1.4.

The Primary Coil features a wire-wound design made from litz wire, comprising 105 strands of no 40 AWG (0.08 mm diameter) or an equivalent material As illustrated in Figure 54, it has a triangular shape and consists of a single layer The dimensions of the Primary Coil are detailed in Table 35.

The WPC has discouraged the development of products based on the Power Transmitter design A due to underperformance in Foreign Object Detection Consequently, they have decided to phase out the registration of new Base Station products utilizing this design The exact cut-off date for this phase-out has not yet been determined.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 55 The shielding must extend at least 2.5 mm beyond the outer diameter of the Primary Coil, with a minimum thickness of 0.5 mm, and should be positioned below the Primary Coil at a maximum distance of $d_s = 1.0$ mm This version of Part 4: Reference Designs specifies that the shielding composition is limited to certain materials.

 Mn-Zn ferrite (any supplier)

The top face of the Primary Coil has a height of \$d z = 2 - 0.5 + 0.5 \, \text{mm}\$ Additionally, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The WPC has discouraged the development of products based on Power Transmitter design A 16 due to underperformance in Foreign Object Detection Consequently, they have decided to phase out the certification of new Base Station products utilizing this design, although the exact cut-off date has yet to be determined.

The WPC has observed that Power Transmitters designed with A 16 underperform in Foreign Object Detection Consequently, they have decided to phase out the registration of new Base Station products based on this design The exact cut-off date for this phase-out has not yet been determined.

If the Base Station contains multiple type A16 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall not overlap

The Power Transmitter design A16, illustrated in Figure 56, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Within the specified operating frequency range, the combination of the Primary Coil, Shielding, and magnet exhibits a self-inductance of $M_P = 6.3 \pm 10\% \, \mu H$ The series capacitance value is also provided.

퐶P= 0.4 ±5% μF The input voltage to the full-bridge inverter is 5 ±5% V

The A16 Power Transmitter design regulates power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 110 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at 205 kHz Increasing the Operating Frequency or decreasing the duty cycle leads to reduced power transfer To ensure precise control over the power transferred, the A16 Power Transmitter must adjust the Operating Frequency with high resolution.

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ within the range of 175 to 205 kHz Additionally, a type A16 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

The WPC has observed that Power Transmitters designed with A 16 underperform in Foreign Object Detection Consequently, they have decided to phase out the registration of new Base Station products based on this design The exact cut-off date for this phase-out has not yet been determined.

The A17 Power Transmitter design facilitates Guided Positioning, as depicted in Figure 57, which showcases its functional block diagram This design comprises two primary components: the Power Conversion Unit and the Communications and Control Unit.

The Power Conversion Unit, illustrated in Figure 57, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and one or more capacitors Additionally, a current sense device monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 57, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the rail voltage of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

The design of the Power Transmitter A17 features a single Primary Coil, as outlined in Section 2.2.17.1.1 It incorporates Shielding, detailed in Section 2.2.17.1.2, an Interface Surface specified in Section 2.2.17.1.3, and an alignment aid described in Section 2.2.17.1.4.

The Primary Coil is constructed from wire-wound type 2 litz wire, specifically no 17 AWG (1.15 mm diameter) with 105 strands of no 40 AWG (0.08 mm diameter) It features a circular shape and is composed of multiple layers, all aligned with the same polarity For detailed dimensions of the Primary Coil, refer to Table 39.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 59 The shielding must extend at least 2 mm beyond the outer diameter of the Primary Coil, have a minimum thickness of 0.5 mm, and be positioned no more than 1.0 mm below the Primary Coil This version of Part 4: Reference Designs specifies that the shielding material must be selected from a designated list of options.

The top face of the Primary Coil has a height of \$d z = 7 - 5.25 + 0.5\text{ mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The Power Transmitter design A17, illustrated in Figure 60, employs a full-bridge inverter to drive a resonant network that includes filter inductors and a primary coil with both series and parallel capacitance The primary coil and shielding assembly exhibit a self-inductance of $ M_P = 24 \pm 10\% \, \mu H $ within the specified operating frequency range The inductances $ M_1 $ and $ M_2 $ are measured at $ 2.2 \pm 20\% \, \mu H $ The total series capacitance is $ C_{ser1} + C_{ser2} = 100 \pm 5\% \, nF $, with individual series capacitances being less than this total Additionally, the parallel capacitance is $ C_{qbr} = 200 \pm 5\% \, nF $.

The Power Transmitter design A17 regulates power transfer by adjusting the input voltage to the inverter, which ranges from 1.4 to 15 V with a resolution of 10 mV or better; higher input voltages lead to increased power transfer It operates at a frequency of 105 to 116 kHz with a duty cycle of 50%.

When a type A17 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), it shall use an input voltage of 5.75 V, and a recommended Operating Frequency of 111 kHz

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage To ensure precise power control, a type A17 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, Table 40 lists various parameters essential for the PID algorithm.

Scaling factor 푇푤 200 mV

Figure 61 illustrates the functional block diagram of this design, which consists of three major functional units, namely a Power Conversion Unit, a Detection Unit, and a Communications and Control Unit

The Power Conversion Unit, depicted on the right side of Figure 61, along with the Detection Unit at the bottom, represents the analog components of the design This unit closely resembles the Power Conversion Unit found in Power Transmitter design A7 It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, a voltage sense component is included to monitor the voltage across the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 61, represents the digital logic component of the design, akin to the Power Transmitter design A7 This unit is responsible for receiving and decoding messages from the Power Receiver, executing power control algorithms and protocols, and regulating the input voltage of the AC waveform to manage power transfer Additionally, it interfaces with other Base Station subsystems for user interface functionalities.

The Detection Unit identifies the approximate locations of objects and Power Receivers on the Interface Surface without specifying a particular detection method It is advisable for the Detection Unit to utilize the resonance of the Power Receiver at the detection frequency $ f_d $, as outlined in the Power Receiver Design Requirements section of Parts 1 and 2: Interface Definitions This method reduces the movement of the Secondary Coil, since the Power Transmitter does not need to alert users about non-responsive objects at this resonant frequency An example of a resonant detection method can be found in Parts 1 and 2: Interface Definitions.

The design of the Power Transmitter A18 features a single Primary Coil, shielding, an Interface Surface, and an alignment aid, as detailed in Sections 2.2.18.1.1 to 2.2.18.1.4.

The Primary Coil features a wire-wound design made from litz wire, comprising 80 strands with a diameter of 0.08 mm Illustrated in Figure 62, the coil is circular and constructed in a single layer For detailed specifications, refer to Table 41, which outlines the dimensions of the Primary Coil.

The top face of the Primary Coil measures \$d z = 2.0 + 1.5 \, \text{mm}\$, while the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The alignment aid provides visual, audible, or tactile cues to assist users in positioning a Power Receiver within the Active Area of the Interface Surface, offering directional and distance feedback for improved accuracy.

The Power Transmitter design A18, illustrated in Figure 64, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Operating within a frequency range of 105 kHz to 140 kHz, the combination of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 13.6 \pm 10\% \, \mu H$ Additionally, the series capacitance is measured at $C_P = 180 \pm 5\% \, nF$.

The A18 Power Transmitter design utilizes input voltage to regulate power transfer through a full-bridge inverter It operates within an input voltage range of 3 to 12 V, where lower voltages correspond to reduced power transfer To ensure precise control over the transferred power, the A18 Power Transmitter must adjust the input voltage with a resolution of 50 mV or finer.

When the type A18 Power Transmitter initially applies a Power Signal, it should use a starting input voltage of 6.5 V and an Operating Frequency of 140 kHz If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it will remove the Power Signal as outlined in the Interface Definitions The Power Transmitter can reapply the Power Signal multiple times at consecutively lower Operating Frequencies within the specified range until it receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the full-bridge inverter To ensure precise power control, a type A18 Power Transmitter will measure the amplitude of the Primary Cell voltage, which corresponds to the Primary Coil voltage, with a resolution of 5 mV or better Additionally, Table 42 lists various parameters essential for the PID algorithm.

Figure 65 illustrates the functional block diagram of this design, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Power Conversion Unit, illustrated in Figure 65, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The Primary Coil is selected from two partially overlapping options based on the Power Receiver's position relative to the coils The selection process involves the Power Transmitter establishing communication with the Power Receiver through the available Primary Coils, while a current sensor monitors the current flowing through the selected Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 65, serves as the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block for the correct Primary Coil connection, and implements power control algorithms and protocols to regulate the AC waveform frequency for effective power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A19 includes two Primary Coils as defined in Section 2.2.19.1.1, Shielding as defined in Section 2.2.19.1.2, and an Interface Surface as defined in Section 2.2.19.1.3

The Primary Coil is constructed from wire-wound type 2 litz wire, featuring 105 strands of no 40 AWG, with a total diameter of 0.81 mm It has a rectangular shape and is designed as a single layer, as illustrated in Figure 66 Detailed dimensions of the Primary Coil can be found in Table 43.

Power Transmitter design A19 contains two overlapping Primary Coils, with coinciding long axes The distance between the Primary Coil centers is 푑cc= 27 ±4 mm See Figure 67

Figure 67 Primary Coils of Power Transmitter design A19 d cc

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 68 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.5 mm, and should be positioned below the Primary Coil at a maximum distance of 1.0 mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

Figure 68 Primary Coil assembly of Power Transmitter design A19 d s dz

The top face of the Primary Coil has a height change of \$dz = 2 - 0.25 + 0.5 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer dimensions of the Primary Coils.

The Power Transmitter design A19 utilizes a half-bridge inverter to operate an individual Primary Coil along with a series capacitance The assembly of Primary Coils and Shielding exhibits a self-inductance of $M_P = 12.2 \pm 10\% \, \mu H$ for coils nearest to the Interface Surface, and $M_P = 12.5 \pm 10\% \, \mu H$ for those furthest away Additionally, the series capacitance values are $C_P = 0.138 \pm 5\% \, \mu F$ for the closest coils and $C_P = 0.136 \pm 5\% \, \mu F$ for the farthest coils The input voltage supplied to the half-bridge inverter is also specified.

The Power Transmitter design A19 regulates power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 115 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at 205 kHz An increase in Operating Frequency or a decrease in duty cycle leads to reduced power transfer To ensure precise control over the power transferred, a type A6 Power Transmitter is employed to adjust the Operating Frequency with high resolution.

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ in the range of 175 to 205 kHz or better Additionally, a type A19 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ in this algorithm signifies the Operating Frequency or duty cycle To ensure precise power control, a type A19 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, the values of various parameters used in the PID algorithm are detailed in Tables 44, 45, and 46.

The Power Conversion Unit, illustrated on the right side of Figure 70, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, voltage and current sensing monitors are employed to track the voltage and current of the Primary Coil.

The soft-magnetic material in the Shielding block effectively protects the Base Station from the magnetic field generated by the Primary Coil The Shielding is designed to align with the top face of the Primary Coil, encasing it on all sides except the top, and extends at least 2.5 mm beyond the coil's outer edge with a minimum thickness of 2.0 mm This version of Part 4: Reference Designs specifies that the Shielding composition must be selected from a designated list of materials.

 Mn-Zn-Ferrite Dust Core — any supplier

 Ni-Zn-Ferrite Core — any supplier

If the Base Station contains multiple type A20 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 65.0 ±0.5 mm.

The Power Transmitter design A20, illustrated in Figure 73, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 24 \pm 10\% \, \mu H$, while the series capacitance is $C_P = 148 \pm 5\% \, nF$.

The Power Transmitter design A20 utilizes the input voltage to the full-bridge inverter to regulate the power transfer It operates within an input voltage range of 2.5 ±0.5 to 11.5 ±0.5 V, achieving a resolution of 10 mV or better, where an increase in input voltage leads to greater power transfer The operating frequency range is set between 87 and 110 kHz.

When the type A20 Power Transmitter initially applies a Power Signal at an Operating Frequency of 98 kHz and an input voltage of 5.5 ±2.0 V, it will remove the Power Signal if it does not receive a Signal Strength Packet from the Power Receiver The Power Transmitter can reapply the Power Signal multiple times at progressively lower Operating Frequencies until it successfully receives a Signal Strength Packet with an appropriate Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies both the Operating Frequency and the input voltage to the full-bridge inverter It is advisable to primarily adjust the Operating Frequency for power control, with voltage adjustments reserved for the limits of the Operating Frequency range To ensure precise power control, a type A20 Power Transmitter must measure the amplitude of the Primary Coil current with a resolution of 5 mA or better Additionally, Table 48 and Table 49 present various parameters essential for the PID algorithm.

Figure 74 illustrates the functional block diagram of this Power Transmitter design A21, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Power Conversion Unit, illustrated in Figure 74, includes the analog components essential for the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The selected Primary Coil is one of at least three partially overlapping coils, chosen based on the Power Receiver's position The selection process involves the Power Transmitter attempting to communicate with the Power Receiver through any of the available Primary Coils, while a current sensor continuously monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 74, is the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block to connect the correct Primary Coil, and implements power control algorithms and protocols Additionally, it regulates the frequency of the AC waveform to manage power transfer and interfaces with other Base Station subsystems for user interface functionalities.

The Primary Coil consists of at least one PCB coil Figure 75 shows a view of a single Primary Coil Table

50 lists the dimensions of the Primary Coil

Track width plus spacing 푑 w + 푑 s 1.08 ±0.2 mm

Track width plus spacing 푑w+ 푑s 1.1 ±0.15 mm

The design of the Power Transmitter A21 features a minimum of one Primary Coil Odd-numbered coils are arranged parallel to one another, with a center displacement of $d h2$ In contrast, even-numbered coils are positioned orthogonally to the odd-numbered coils, maintaining a center displacement of $d h1$ mm.

Center-to-center distance 푑 h1 23.8 ±1.0 mm

PCB copper thickness 푑 Cu 0.105 ±0.015 mm

Center-to-center distance 푑 h2 47.52 ±3 mm

PCB copper thickness 푑 Cu 0.105 ±0.0161 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 78 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.8 mm, and should be positioned below the Primary Coil at a maximum distance of 1.0 mm This section of Part 4: Reference Designs specifies that the shielding material must be selected from a designated list of options.

The measurement of \$dz\$ is 2.75 ± 1 mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 0.5 mm beyond the outer dimensions of the Primary Coils.

The Power Transmitter design A21 utilizes a half-bridge inverter to operate an individual Primary Coil along with a series capacitance The assembly of Primary Coils and Shielding exhibits a self-inductance of $M_P = 11.5 \pm 10\% \, \mu H$ for coils nearest to the Interface Surface, and $M_P = 12.5 \pm 10\% \, \mu H$ for those furthest away Additionally, the series capacitance values are $C_P = 0.147 \pm 5\% \, \mu F$ for the closest coils and $C_P = 0.136 \pm 5\% \, \mu F$ for the farthest coils The input voltage supplied to the half-bridge inverter is also specified.

The A21 Power Transmitter design regulates power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 115 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at 205 kHz Increasing the Operating Frequency or decreasing the duty cycle leads to reduced power transfer To ensure precise control over the power transferred, the A21 Power Transmitter must adjust the Operating Frequency with high resolution.

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ in the range of 175 to 205 kHz or better Additionally, a type A21 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ in this algorithm signifies the Operating Frequency or duty cycle To ensure precise power control, a type A21 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, the values of various parameters used in the PID algorithm can be found in Tables 52, 53, and 54.

The Power Conversion Unit, illustrated on the right side of Figure 80, includes the analog components of the design It features voltage and current sensing to monitor the input levels, while the inverter transforms the DC input into an AC waveform that powers a resonant circuit, comprising the Primary Coil and a series capacitor.

Outer width 푑ow 57.1 ±0.5 mm

Inner width 푑 iw 4.5 ±0.5 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 82 The Shielding encompasses the Primary Coil on all sides except the top face and extends at least 2.5 mm beyond its outer edge, with a minimum thickness of 2.0 mm This version of Part 4: Reference Designs specifies that the Shielding composition is limited to a selection from designated materials.

 Mn-Zn-Ferrite Core – any supplier

 Sendust-Ferrite Core – any supplier

The measurement of the top face of the Primary Coil shows a variation of \$d z = 2.5 \pm 1.0 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The Power Transmitter design A22, illustrated in Figure 83, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Within the specified operating frequency range, the combination of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 19.0 \pm 10\% \, \mu H$, while the series capacitance is $C_P = 122 \pm 10\% \, nF$.

The Power Transmitter design A22 regulates power transfer by utilizing the input voltage to the full-bridge inverter, along with its operating frequency and duty cycle It operates within an input voltage range of 2 to 12 V, achieving a resolution of 10 mV or better The operating frequency spans from 110 to 205 kHz, while the duty cycle varies between 2% and 50%.

When a type A22 Power Transmitter initially applies a Power Signal, it operates at a frequency of 125 ±10 kHz and an input voltage of 3.5 to 7.5 V If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it will discontinue the Power Signal as outlined in the Interface Definitions The Power Transmitter can reapply the power signal multiple times, increasing the input voltage within the specified range, until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the full-bridge inverter, along with the operating frequency and duty cycle It is advisable to primarily manage power control through adjustments to the input voltage To ensure precise power control, a type A22 Power Transmitter must measure the amplitude of the Primary Coil current with a resolution of 5 mA or better Additionally, the values of various parameters used in the PID algorithm are detailed in Tables 56, 57, and 58.

Integral gain 퐿 i 0 mA-1ms-1

Derivative gain 퐿d 0 mA-1ms

Table 58 PID parameters for duty control

The Power Conversion Unit, illustrated in Figure 84, includes the analog components of the design It features voltage and current sensing to monitor the input levels, while the inverter transforms the DC input into an AC waveform that powers a resonant circuit, comprising the Primary Coil and a series capacitor.

The Primary Coil features a wire-wound design made from litz wire, comprising 115 strands with a diameter of 0.08 mm As illustrated in Figure 85, it has a racetrack-like shape and consists of a single layer The dimensions of the Primary Coil are detailed in Table 59.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 86 The Shielding encompasses the Primary Coil on all sides except the top face and extends at least 2.5 mm beyond its outer edge, with a minimum thickness of 2.0 mm This version of Part 4: Reference Designs specifies that the Shielding material must be selected from a designated list of options.

The Power Transmitter design A23, illustrated in Figure 87, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 19.0 \pm 10\% \, \mu H$, while the series capacitance is $C_P = 168 \pm 10\% \, nF$.

The Power Transmitter design A23 regulates power transfer by utilizing the input voltage to the full-bridge inverter, along with its operating frequency and duty cycle It operates within an input voltage range of 2 to 12 V, achieving a resolution of 10 mV or better The operating frequency spans from 101 to 115 kHz, while the duty cycle varies between 2% and 50%.

When a type A23 Power Transmitter initially applies a Power Signal, it operates at a frequency of 108 ±5 kHz and an input voltage of 3.5 to 7.5 V If the Power Transmitter does not receive a Signal Strength Packet from the Power Receiver, it will discontinue the Power Signal as outlined in the Interface Definitions The Power Transmitter can reapply the power signal multiple times, increasing the input voltage within the specified range, until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the input voltage to the full-bridge inverter, along with the operating frequency and duty cycle It is advisable to primarily adjust the input voltage for effective power control To ensure accurate power management, a type A23 Power Transmitter must measure the amplitude of the Primary Coil current with a resolution of 5 mA or better Additionally, Tables 60, 61, and 62 present various parameter values essential for the PID algorithm.

Integral gain 퐿 i 0 mA-1ms-1

Derivative gain 퐿 d 0 mA-1ms

The Power Conversion Unit, illustrated on the right side of Figure 88, includes the analog components of the design It features voltage and current sensing to monitor the input levels, while the inverter transforms the DC input into an AC waveform that powers a resonant circuit, comprising the Primary Coil and a series capacitor.

The Primary Coil features a wire-wound design made from litz wire, comprising 105 strands with a diameter of 0.08 mm Illustrated in Figure 89, the Primary Coil is circular and consists of a single layer For detailed specifications, refer to Table 63, which outlines the dimensions of the Primary Coil.

Soft-magnetic material safeguards the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 90 The Shielding extends at least 2.0 mm beyond the Primary Coil's outer edge and has a minimum thickness of 0.5 mm This version of Part 4: Reference Designs restricts the Shielding materials to a specified list.

 Ni-Mn-Ferrite Core – any supplier

The Power Transmitter design A24, illustrated in Figure 91, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 6.1 \pm 10\% \, \mu H$ The series capacitance is valued at $C_P = 400 \pm 10\% \, nF$, and the input voltage to the full-bridge inverter is set at $5.0 \pm 5\% \, V$.

The A24 Power Transmitter design regulates power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal The Operating Frequency ranges from 110 to 205 kHz, while the duty cycle varies between 2% and 50% A higher Operating Frequency combined with a lower duty cycle leads to reduced power transfer To ensure precise control over the transferred power, the A24 Power Transmitter must adjust the Operating Frequency with a resolution of 0.1 kHz or better.

When a type A24 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), the Power Transmitter shall use an Operating Frequency of 155 ±15 kHz, and a duty cycle of

The Power Transmitter will eliminate the Power Signal if it does not receive a Signal Strength Packet from the Power Receiver, as outlined in Parts 1 and 2: Interface Definitions It may attempt to reapply the power signal several times across the specified operating frequency range until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the input voltage to the full-bridge inverter, operating frequency, and duty cycle It is advisable to primarily adjust the duty cycle for effective power control To ensure accurate power management, a type A24 Power Transmitter will measure the amplitude of the primary coil current with a resolution of 5 mA or better Additionally, Tables 64 and 65 present various parameters essential for the PID algorithm.

The Power Conversion Unit, illustrated in Figure 92, includes the analog components of the design It features voltage and current sensing to monitor the input levels, while the inverter transforms the DC input into an AC waveform that powers a resonant circuit, consisting of a Primary Coil and a series capacitor.

The Communications and Control Unit, depicted on the left side of Figure 92, serves as the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the input power and frequency of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Number of turns per layer 푂 11 (bifilar turns)

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 94 The Shielding extends a minimum of 2.5 mm beyond the outer edge of the Primary Coil and has a thickness of at least 2.0 mm This version of Part 4: Reference Designs restricts the Shielding materials to a specified list.

The measurement of the top face of the Primary Coil shows a variation of \$d z = 2.5 \pm 1.0 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

If the Base Station contains multiple type A25 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 67.2 mm.

The Power Transmitter design A25, illustrated in Figure 95, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 6.1 \pm 10\% \, \mu H$ The series capacitance is valued at $C_P = 400 \pm 10\% \, nF$, and the input voltage to the full-bridge inverter is set at $5.0 \pm 5.0\% \, V$.

The A25 Power Transmitter design utilizes the Operating Frequency and duty cycle of the Power Signal to regulate the power transfer The Operating Frequency ranges from 110 to 205 kHz, while the duty cycle varies between 2% and 50% A higher Operating Frequency combined with a lower duty cycle leads to reduced power transfer To ensure precise control over the transferred power, the A25 Power Transmitter must adjust the Operating Frequency with a resolution of 0.1 kHz or better.

The Power Transmitter will eliminate the Power Signal if it does not receive a Signal Strength Packet from the Power Receiver, as outlined in Parts 1 and 2: Interface Definitions It may attempt to reapply the power signal several times at progressively lower Operating Frequencies within the specified range until it successfully receives a Signal Strength Packet with an acceptable Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the input voltage to the full-bridge inverter, operating frequency, and duty cycle It is advisable to primarily adjust the duty cycle for effective power control To ensure accurate power management, a type A25 Power Transmitter must measure the amplitude of the primary coil current with a resolution of 5 mA or better Additionally, Tables 67 and 68 list various parameters essential for the PID algorithm.

The design of the Power Transmitter A26 features a single Primary Coil, as outlined in Section 2.2.26.1.1 It incorporates Shielding, detailed in Section 2.2.26.1.2, an Interface Surface specified in Section 2.2.26.1.3, and an alignment aid described in Section 2.2.26.1.4.

The Primary Coil features a wire-wound design made from litz wire, comprising 105 strands of 40 AWG (0.08 mm diameter) or equivalent As illustrated in Figure 97, it has a triangular shape and consists of a single layer The dimensions of the Primary Coil are detailed in Table 69.

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 98 The shielding must extend at least 2.5 mm beyond the outer diameter of the Primary Coil, with a minimum thickness of 0.7 mm, and should be positioned below the Primary Coil at a maximum distance of $d_s = 1.0$ mm This version of Part 4: Reference Designs specifies that the shielding composition is limited to certain materials.

 Mn-Zn ferrite (any supplier)

The top face of the Primary Coil has a thickness of \$d z = 2 - 0.5 + 0.5 \, \text{mm}\$ Additionally, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

If the Base Station contains multiple type A26 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall not overlap

The Power Transmitter design A26, illustrated in Figure 99, employs a full-bridge inverter to energize the Primary Coil along with a series capacitance Within the specified operating frequency range, the combination of the Primary Coil, Shielding, and magnet exhibits a self-inductance of $M_P = 6.3 \pm 10\% \, \mu H$ The series capacitance value is also provided.

퐶P= 0.4 ±5% μF The input voltage to the full-bridge inverter is 5 ±5% V

The formula \$0.015 \times f_{op} - 1.58 \text{ kHz}\$ applies for \$f_{op}\$ within the range of 175 to 205 kHz or better Additionally, a type A26 Power Transmitter is required to manage the duty cycle of the Power Signal with a resolution of 0.1% or higher.

When a type A26 Power Transmitter first applies a Power Signal (see Parts 1 and 2: Interface Definitions), it shall use an initial Operating Frequency of 175 kHz (and a duty cycle of 50%)

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the Operating Frequency or duty cycle To ensure precise power control, a type A16 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, the values of various parameters used in the PID algorithm are detailed in Tables 70, 71, and 72.

The Power Conversion Unit, illustrated on the right side of Figure 100, includes the analog components of the design It features an impedance matching network that creates a resonant circuit with the Primary Coil Additionally, the sensing circuits track the current and voltage of the Primary Coil, while the inverter transforms the DC input into an AC waveform to power the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 100, is the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the inverter to manage power delivery to the Power Receiver Additionally, this unit connects with other Base Station subsystems for user interface functionalities.

Power Transmitter design A27 includes a Primary Coil array as defined in Section 2.2.27.1.1, Shielding as defined in Section 2.2.27.1.2, and an Interface Surface as defined in Section 2.2.27.1.3

The Primary Coil is a wire-wound type made from 17 AWG (1.15 mm diameter) type 2 litz wire, featuring 105 strands of no 40 AWG (0.08 mm diameter) or equivalent It has a circular shape and consists of a single layer, as illustrated in Figure 101 The dimensions of the Primary Coil are detailed in Table 73.

Transmitter design A27 utilizes Shielding to safeguard the Base Station from the magnetic field produced by the Primary Coil This Shielding extends at least 2 mm beyond the outer edges of the Primary Coil array and is positioned no more than 0.5 mm below the array.

The Shielding is made from soft magnetic material with a minimum thickness of 0.5 mm In Part 4: Reference Designs, the composition of the Shielding is restricted to specific materials from a designated list.

 FK2 — TDK Corp (at least 0.8mm thickness)

Figure 102 Primary Coil array assembly of Power Transmitter design A27

푑z= 2 −0.5 +0.5 mm, across the top face of the Primary Coil In addition, the Interface Surface extends at least

5 mm beyond the outer edges of the Primary Coil array

The Power Transmitter design A27, illustrated in Figure 103, employs a full-bridge inverter to operate a resonant network that includes a filter inductor and a Primary Coil with both series and parallel capacitance The system functions within an operating frequency range of \$f_{op} = 110 \ldots 120 \text{ kHz}\$, featuring a Primary Coil and Shielding assembly with an inductance of \$24.0 \pm 10\% \, \mu\text{H}\$ The impedance matching circuit comprises an inductance of \$M_m = 8.2 \pm 20\% \, \mu\text{H}\$, a series capacitance of \$C_{ser} = 100 \pm 5\% \, \text{nF}\$, and a parallel capacitance of \$C_{par} = 100 \pm 5\% \, \text{nF}\$ The full-bridge inverter receives an input voltage of \$12 \pm 5\% \, \text{V}\$.

NOTE Near resonance, the voltage developed across the series capacitance can reach levels exceeding 100V pk-pk

The A27 Power Transmitter design utilizes the phase difference between control signals in the full-bridge inverter to regulate power transfer, as illustrated in Figure 104 The phase difference, denoted as 훼, ranges from 0 to 180°, with larger differences leading to reduced power transfer To ensure precise power adjustment, the A27 Power Transmitter must control the phase difference with a resolution of 0.42° or better Upon the initial application of a Power Signal (Digital Ping), the A27 Power Transmitter will set the phase difference to 120°.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the phase difference between the two halves of the full-bridge inverter To ensure precise power control, a type A27 Transmitter must measure the current amplitude into the Primary Coil with a resolution of 7 mA or better Additionally, Table 74 lists various parameters essential for the PID algorithm.

Figure 104 Control signals to the inverter

Table 74 Control parameters for power control

Figure 105 illustrates the functional block diagram of this Power Transmitter design A28, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Power Conversion Unit, illustrated in Figure 105, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The Primary Coil is selected from three partially overlapping options based on the Power Receiver's position The selection process involves the Power Transmitter attempting to communicate with the Power Receiver using one of the Primary Coils, while a current sensor monitors the current flowing through the selected Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 105, integrates both analog circuits and digital logic It decodes messages from the Power Receiver, configures the Coil Selection block for the correct Primary Coil connection, and implements power control algorithms and protocols to regulate the AC waveform frequency for power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A28 includes one or more Primary Coils as defined in Section 2.2.28.1.1, Shielding as defined in Section 2.2.28.1.2, and Interface Surface as defined in Section 2.2.28.1.3

The Primary Coil is a wire-wound type made from 17 AWG (1.15 mm diameter) type 2 litz wire, featuring 105 strands of 40 AWG (0.08 mm diameter) wire It has a rectangular shape and is constructed in a single layer, with its dimensions detailed in Table 75.

Outer length 푑푝푚 47.5 ±1.0 mm

Inner length 푑푖푚 28.0 ±1.0 mm

Outer width 푑 푝푥 39.5 ±1.0 mm

Inner width 푑푖푥 19.5 ±1.0 mm

Number of turns per layer N 9

The Power Transmitter design A28 features one or more Primary Coils, with at least one Primary Coil present Odd numbered coils are arranged side by side, maintaining a center-to-center displacement of \$d_{oo} = 49.2 \pm 4 \, \text{mm}\$ In contrast, even numbered coils are positioned orthogonally to the odd numbered coils, with a center-to-center displacement of \$d_{oe} = 24.6 \pm 2 \, \text{mm}\$ Refer to Figure 107 for a visual representation.

Soft-magnetic material serves to shield the Base Station from the magnetic field produced by the Primary Coils, as illustrated in Figure 108 This shielding must cover at least the outer dimensions of the Primary Coils, have a minimum thickness of 0.5 mm, and be positioned beneath the Primary Coils at a maximum distance.

푑s = 1.0 mm This version of Part 4: Reference Designs limits the composition of the Shielding to a choice from the following list of materials:

The distance from the Primary Coil to the Interface Surface of the Base Station is calculated as $ dz = 2 - 0.25 + 0.5 $ mm, measured across the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer dimensions of the Primary Coils.

The Power Transmitter design A28 utilizes a full-bridge inverter to operate an individual Primary Coil along with a series capacitance The assembly of Primary Coils and Shielding exhibits a self-inductance of 6.4 ±10% μH for the coils nearest to the Interface Surface and 6.9 ±10% μH for those furthest away Additionally, the series capacitance values are 400 ±5% nF for the closest coils and 357 ±5% nF for the farthest The input voltage supplied to the full-bridge inverter is 5 ±5% V.

The A28 Power Transmitter design regulates power transfer by adjusting the Operating Frequency and duty cycle of the Power Signal It operates within a frequency range of \$f_{op} = 115 \ldots 205 \text{ kHz}\$ at a 50% duty cycle, with a duty cycle range of 10% to 50% at 205 kHz Higher Operating Frequencies or lower duty cycles lead to reduced power transfer To ensure precise control over the power transferred, the A28 Power Transmitter must adjust the Operating Frequency with a high resolution.

 0.01 × 푓op− 0.7 kHz, for 푓op in the 115…175 kHz range;

The power signal must be controlled by a type A28 Power Transmitter, ensuring a duty cycle resolution of 0.1% or better This is applicable for frequencies in the range of 175 to 205 kHz, with a specific formula of 0.015 × \$f_{op} - 1.58\$ kHz.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the Operating Frequency or duty cycle To ensure precise power control, a type A28 Power Transmitter must measure the amplitude of the Primary Cell current, which corresponds to the Primary Coil current, with a resolution of 7 mA or better Additionally, the values of various parameters used in the PID algorithm are detailed in Tables 76, 77, and 78.

Proportional gain 퐿푞 10 mA −1

Integral gain 퐿푖 0.05 mA −1 ms −1

Derivative gain 퐿 푒 0 mA −1 ms

Integral term limit 푁퐼 3,000 N.A

PID output limit 푁푄퐼퐷 20,000 N.A

Frequency Range [kHz] Scaling Factor 푺퐯 [Hz]

Proportional gain 퐿 푞 10 mA −1

Integral gain 퐿 푖 0.05 mA −1 ms −1

Derivative gain 퐿푒 0 mA −1 ms

Integral term limit 푁퐼 3,000 N.A

PID output limit 푁푄퐼퐷 20,000 N.A

Figure 110 illustrates the functional block diagram of Power Transmitter Design A29

Figure 110 Functional block diagram of Power Transmitter A29

The Power Conversion Unit, illustrated in Figure 110, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, voltage and current sensing monitors are employed to track the voltage and current of the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 110, serves as the digital logic component of the design It decodes messages from the Power Receiver, implements power control algorithms, and regulates the input power and frequency of the AC waveform to manage power transfer Additionally, this unit interfaces with other Base Station subsystems for user interface functionalities.

Power Transmitter design A29 includes a Primary Coil array as defined in Section 2.2.29.1.1, Shielding as defined in Section 2.2.29.1.2, and an Interface Surface as defined in Section 2.2.29.1.3

The Primary Coil is a wire-wound type made of litz wire with nylon spinning, featuring 180 strands of no 40 AWG (0.08 mm diameter) or equivalent It has a circular shape with two layers and a total of 13 turns, as illustrated in Figure 111 The dimensions of the Primary Coil are detailed in Table 79.

Figure 111 Primary Coil of Power Transmitter A29

Numbers of turns per layer 푂 6.5

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 112 The shielding must extend at least 3.5 mm beyond the outer diameter of the Primary Coil, with a minimum thickness of 2.5 mm, and should be positioned no more than 1.0 mm below the Primary Coil This version of Part 4: Reference Designs specifies that the shielding composition is limited to a selection from designated materials.

The measurement of \$d z\$ is 2.5 ± 0.5 mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The distance from the Primary Coil to the Interface Surface indicates that the maximum tilt angle between the Primary Coil and a flat Interface Surface is 1.0° For non-flat Interface Surfaces, this distance suggests a minimum radius of curvature of 317 mm, centered on the Primary Coil.

The Power Transmitter design A29, illustrated in Figure 113, employs a full-bridge inverter to drive a resonant network featuring a primary coil with series capacitance Within the specified operating frequency range, the assembly of the primary coil and shielding exhibits a self-inductance of $M_p = 10 \pm 10\% \, \mu H$ Additionally, the total series capacitance is $C_p = 247 \pm 5\% \, nF$, with individual series capacitances being any value less than the total.

The Power Transmitter design A29 regulates power transfer by adjusting the input voltage to the inverter, which ranges from 1 ±5% to 12 ±5% V with a resolution of 40 mV or better A higher input voltage leads to increased power transfer Additionally, it operates at a frequency of 130 ±3% kHz with a duty cycle of 50%.

When a type A29 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), it shall use an Operating Frequency of 130 kHz and a recommended input voltage of 4 V

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ in this algorithm signifies the input voltage Additionally, Table 80 lists various parameters essential for the PID algorithm's implementation.

Figure 113 Electrical diagram (outline) Primary Coil of Power Transmitter design A29

Integral Gain 퐿i 0.05 mA -1 ms -1

Derivative Gain 퐿d 0 mA -1 ms -1

Figure 114 illustrates the functional block diagram of the Power Transmitter design A30, which consists of two major functional units, namely a Power Conversion Unit and a Communications and Control Unit

The Power Conversion Unit, illustrated on the right side of Figure 114, includes the analog components of the design It features voltage and current sensing to monitor the system's voltage and current levels Additionally, the inverter transforms the DC input into an AC waveform that powers a resonant circuit, which is made up of the Primary Coil and a series capacitor.

The Primary Coil features a wire-wound design made from litz wire, comprising 115 strands with a diameter of 0.08 mm Its racetrack-like shape is depicted in Figure 115, and it is constructed with a single layer For detailed specifications, refer to Table 81, which outlines the dimensions of the Primary Coil.

Inner length 푑 il 16.5 ±0.5 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 116 The shielding must extend at least 2.5 mm beyond the outer edge of the Primary Coil and have a minimum thickness of 2.0 mm According to Part 4: Reference Designs, the composition of the shielding is restricted to specific materials from a designated list.

The measurement of \$dz\$ is 5 ± 1.0 mm on the top face of the Primary Coil, while the Interface Surface of the Base Station extends a minimum of 5 mm beyond the outer diameter of the Primary Coil.

The Power Transmitter design A30, illustrated in Figure 117, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance Within the specified operating frequency range, the assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 24.0 \pm 10\% \, \mu H$ The input voltage for the full-bridge inverter is set at $12 \pm 5\% \, V$, while the series capacitance is valued at $C_P = 100 \pm 10\% \, nF$.

The A30 Power Transmitter design utilizes the operating frequency and duty cycle of the power signal to regulate the power transfer It operates within a frequency range of 110 to 205 kHz and a duty cycle range of 2% to 50%.

The Power Transmitter operates within a range of 25 ±15% If it fails to receive a Signal Strength Packet from the Power Receiver, it will deactivate the Power Signal as outlined in Parts 1 and 2: Interface Definitions The Power Transmitter has the capability to reapply the Power Signal multiple times, increasing the duty cycle to the full-bridge inverter, until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ represents the Operating Frequency and duty cycle of the full-bridge inverter It is advisable to primarily adjust the Operating Frequency for power control, with duty cycle modifications based on current levels To ensure precise power management, a type A30 Power Transmitter must measure the Primary Coil current with a resolution of 5 mA or better Additionally, Tables 82 and 83 list various parameters essential for the PID algorithm.

The Power Conversion Unit, illustrated in Figure 118, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which powers a resonant circuit made up of the Primary Coil and a series capacitor Additionally, voltage and current sensing monitors are employed to track the voltage and current of the Primary Coil.

Inner length 푑 il 16.5 ±0.5 mm

Inner width 푑 iw 4.5 ±0.5 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 120 The shielding must extend at least 2.5 mm beyond the outer edge of the Primary Coil and have a minimum thickness of 2.0 mm This version of Part 4: Reference Designs restricts the shielding materials to a specified list.

 Mn-Zn-Ferrite Core - any supplier

 Ni-Zn Ferrite Core – any supplier

The measurement of the top face of the Primary Coil is \$d z = 3.0 \pm 0.5 \, \text{mm}\$ Furthermore, the Interface Surface of the Base Station extends a minimum of \$5.0 \, \text{mm}\$ beyond the outer diameter of the Primary Coil.

If the Base Station contains multiple type A31Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 71.0 mm

The Power Transmitter design A31, illustrated in Figure 121, employs a full-bridge inverter to drive the Primary Coil along with a series capacitance The assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 24 \pm 10\% \, \mu H$ within the specified operating frequency range The input voltage supplied to the full-bridge inverter is $12 \pm 5\% \, V$, and the series capacitance is valued at $C_P = 148 \pm 5\% \, nF$.

The Power Transmitter design A31 regulates the power transfer by utilizing the Operating Frequency and duty cycle of the Power Signal Specifically, the Operating Frequency ranges from 87 to 110 kHz, while the duty cycle varies between 2% and 50%.

When a type A31 Power Transmitter first applies a Power Signal (Digital Ping; see Parts 1 and 2: Interface Definitions), the Power Transmitter shall use an Operating Frequency of 98 ±10.0 kHz, and a duty cycle of

The Power Transmitter operates within a range of 25 ±10.0% If it fails to receive a Signal Strength Packet from the Power Receiver, it will deactivate the Power Signal as outlined in Parts 1 and 2: Interface Definitions The Power Transmitter has the capability to reapply the Power Signal multiple times at increasing duty cycles to the full bridge inverter until it successfully receives a Signal Strength Packet with a valid Signal Strength Value.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies both the Operating Frequency and the duty cycle for the full-bridge inverter It is advisable to primarily adjust the Operating Frequency for power control, with duty cycle modifications based on current levels To ensure precise power management, a type A31 Power Transmitter must measure the Primary Coil current with a resolution of 5 mA or better Additionally, Table 85 and Table 86 present various parameters essential for the PID algorithm.

The Power Conversion Unit, illustrated in Figure 122, includes the analog components essential for the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The Primary Coil is selected from a linear array of partially overlapping coils, depending on the Power Receiver's position The selection process involves the Power Transmitter establishing communication with the Power Receiver through any available Primary Coil, although if only one coil is present, the selection is straightforward Additionally, a current sensor monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 122, is the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block to connect the correct Primary Coil, and implements power control algorithms and protocols Additionally, it regulates the frequency of the AC waveform to manage power transfer and interfaces with other Base Station subsystems for user interface functionalities.

Track width plus spacing 푑 w +푑 s 1.08 ±0.2 mm

Track width plus spacing 푑w+푑s 1.1 ±0.15 mm

The Power Transmitter design A32 features a minimum of one Primary Coil, with odd-numbered coils arranged parallel to each other, maintaining a center displacement of $d_{h2}$ In contrast, even-numbered coils are oriented orthogonally to the odd-numbered coils, with a center displacement of $d_{h1}$ mm.

Center-to-center distance 푑h1 23.8 ±1.0 mm

PCB copper thickness 푑Cu 0.105 ±0.015 mm

Center-to-center distance 푑h2 47.52 ±3.0 mm

PCB copper thickness 푑Cu 0.105 ±0.0161 mm

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 126 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.5 mm, and should be positioned beneath the Primary Coil at a maximum distance of 1.0 mm (denoted as $d_s$) According to Part 4: Reference Designs, the materials for the shielding are restricted to a specified list.

 Ni-Zn- Ferrite Core – any supplier

The measurement of \$d z\$ is 2.75 ± 1 mm on the top face of the Primary Coil Furthermore, the Interface Surface of the Base Station extends a minimum of 0.5 mm beyond the outer dimensions of the Primary Coils.

The Power Transmitter design A32 utilizes a full-bridge inverter to drive a Primary Coil and series capacitance, as illustrated in Figure 117 The assembly of the Primary Coil and Shielding exhibits a self-inductance of $M_P = 11.5 \pm 10\% \, \mu H$ for coils nearest to the interface surface, and $M_P = 12.5 \pm 10\%$ for those furthest away The inductance values $M_1$ and $M_2$ are $1 \pm 20\% \, \mu H$ The total series capacitance is calculated as $1/C_{ser1} + 1/C_{ser2} = 1/200 \pm 10\% \, 1/nF$, while the parallel capacitance is $C_{par} = 400 \pm 10\% \, nF$.

NOTE Near resonance, the voltage developed across the series capacitance can reach levels exceeding 100 V pk-pk Power

The A32 Power Transmitter design regulates power transfer by utilizing the inverter's input voltage, which ranges from 1 to 12 V with a precision of 10 mV or better It operates at a frequency between 105 and 115 kHz, maintaining a duty cycle of 50%.

The A32 Power Transmitter initiates a Power Signal (Digital Ping) by applying an initial voltage of 3.5±0.5 V to the bottom Primary Coil and 3.0±0.5 V to the top Primary Coil, with a recommended Operating Frequency of 110 kHz.

The power transfer control will utilize the PID algorithm as outlined in Parts 1 and 2: Interface Definitions The controlled variable $ w(i) $ signifies the input voltage to the inverter To ensure precise power control, a type A32 Power Transmitter will measure the amplitude of the Primary Cell current, which matches the Primary Coil current, with a resolution of 7 mA or better Additionally, Table 89 lists various parameters essential for the PID algorithm.

Integral gain 퐿i 0.01 mA-1ms-1

Derivative gain 퐿 d 0 mA-1ms

The Power Transmitter design A33 allows for flexible positioning of the Power Receiver As shown in Figure 128, this design features a functional block diagram that includes two primary components: the Power Conversion Unit and the Communications and Control Unit.

The Power Conversion Unit, illustrated in Figure 128, includes the analog components of the design It features an inverter that transforms the DC input into an AC waveform, which energizes a resonant circuit made up of a chosen Primary Coil and a series capacitor The selected Primary Coil is part of a linear array of partially overlapping coils, tailored to the Power Receiver's position The Power Transmitter initiates the selection process by attempting to communicate with the Power Receiver through any of the available Primary Coils, although the selection is straightforward if only one coil is present Additionally, a current sensor monitors the current flowing through the Primary Coil.

The Communications and Control Unit, depicted on the left side of Figure 128, serves as the digital logic component of the design It decodes messages from the Power Receiver, configures the Coil Selection block to connect the correct Primary Coil, and implements power control algorithms and protocols Additionally, it regulates the frequency of the AC waveform to manage power transfer and interfaces with other Base Station subsystems for user interface functionalities.

Outer length 푑푝푚 55.5 ±0.2 mm

Inner length 푑푖푚 27.9 ±0.2 mm

Outer width 푑 푝푥 44.8 ±0.2 mm

Inner width 푑푖푥 18.4 ±0.2 mm

Track width 푑푥 0.6 ±0.2 mm

Outer Corner rounding* 푆 푝푑 16.5 ±0.2 mm

Inner Corner rounding** 푆푖푑 2.7 ±0.2 mm

The Power Transmitter design A33 features a minimum of one Primary Coil, with odd-numbered coils arranged side by side, separated by a center displacement of $d_{oo}$ In contrast, even-numbered coils are positioned orthogonally to the odd-numbered coils, maintaining a center displacement of $d_{oe}$ Refer to Figures 130 and 131 for visual representation, while Table 91 provides the dimensions of the Primary Coils.

Figure 130 Three Primary Coils of Power Transmitter design A33

Figure 131 Four Primary Coils of Power Transmitter design A33

Center-to-center distance 푑푝푝 49.2 ±0.2 mm

Center-to-center distance 푑푝푓 24.6 ±0.2 mm

PCB copper thickness 푑푑푣 105 μm

The layered structure of the Primary Coils array is illustrated in Figure 132 A single coil configuration utilizes one metal layer, while configurations with two or three coils require two metal layers For configurations with four or more coils, three metal layers are employed.

Figure 132 Layered structure of the Primary Coils of Power Transmitter design A33

Soft-magnetic material is utilized to shield the Base Station from the magnetic field produced by the Primary Coil, as illustrated in Figure 133 The shielding must cover at least the outer dimensions of the Primary Coils, with a minimum thickness of 0.5 mm, and should be positioned beneath the Primary Coil at a maximum distance of 1.0 mm This section of Part 4: Reference Designs specifies that the shielding materials must be selected from a designated list.

The distance from the Primary Coil to the Interface Surface of the Base Station is measured at $ dz = 3 \pm 1 $ mm across the top face of the Primary Coil, while for a single Primary Coil, this distance is $ dz = 4.5 \pm 1 $ mm Furthermore, the Interface Surface of the Base Station extends at least 5 mm beyond the outer dimensions of the Primary Coils.

If the Base Station contains multiple type A33 Power Transmitters, the Primary Coils of any pair of those Power Transmitters shall have a center-to-center distance of at least 49.2 ±4 mm.

Baseline Power Profile designs that activate multiple Primary Coils simultaneously

Extended Power Profile Power Transmitter designs

Power Receiver example 1 (5W)

Power Receiver example 2 (5W)

Power Receiver example 3 (8 W)

Tiêu đề	IEC PAS 63095-2:2017-06 - The Qi wireless power transfer system – Power class 0 specification – Part 2: Reference Designs
Thể loại	Standards Document
Năm xuất bản	2017
Thành phố	Geneva

Định dạng
Số trang	314
Dung lượng	7,56 MB

Iec pas 63095 2 2017

Introduction

Scope

Current Specification structure (introduced in version )

Earlier Specification structure (version 1.2.0 and below)

Main features

Conformance and references

Conformance

References

Definitions

Acronyms

Symbols

Conventions

Cross references

Informative text

Terms in capitals

Units of physical quantities

Decimal separator

Notation of numbers

Bit ordering in a byte

Byte numbering

Multiple-bit fields

Operators

Exclusive-OR

Concatenation

Measurement equipment

Introduction

Baseline Power Profile designs that activate a single Primary Coil at a time

Power Transmitter design A1

Power Transmitter design A2

Power Transmitter design A3

Power Transmitter design A4

Power Transmitter design A5

Power Transmitter design A6

Power Transmitter design A7

Power Transmitter design A8

Power Transmitter design A9

Power Transmitter design A10

Power Transmitter design A11

Power Transmitter design A12

Power Transmitter design A13

Power Transmitter design A14

Power Transmitter design A15

Power Transmitter design A16

Power Transmitter design A17

Power Transmitter design A18

Power Transmitter design A19

Power Transmitter design A20

Power Transmitter design A21

Power Transmitter design A22

Power Transmitter design A23

Power Transmitter design A24

Power Transmitter design A25

Power Transmitter design A26

Power Transmitter design A27

Power Transmitter design A28

Power Transmitter design A29

Power Transmitter design A30

Power Transmitter design A31

Power Transmitter design A32

Power Transmitter design A33

Baseline Power Profile designs that activate multiple Primary Coils simultaneously

Extended Power Profile Power Transmitter designs

Power Receiver example 1 (5W)

Power Receiver example 2 (5W)

Power Receiver example 3 (8 W)

Power Receiver example 4 (15 W)

Power Receiver example 5 (12 W)