ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R.. ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R.. ELECTRICAL ENGINEERING:
Trang 1ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Chapter 12 Field-Effect Transistors
Trang 2ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Chapter 12 Field-Effect Transistors
1 Understand MOSFET operation.
2 Analyze basic FET amplifiers using
the load-line technique.
3 Analyze bias circuits.
Trang 3ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
4 Use small-signal equivalent circuits to
analyze
FET amplifiers.
5 Compute the performance
parameters of several
FET amplifier configurations.
6 Select a FET amplifier configuration
that is
appropriate for a given application.
7 Understand the basic operation of
CMOS logic
gates.
Trang 4ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
NMOS AND PMOS TRANSISTORS
Trang 5ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
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Trang 8Operation in the Cutoff Region
to GS
i = 0 for ≤
Trang 9ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 10Operation in the Triode Region
Trang 11ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 12Operation in the Saturation Region
to GS
Trang 13ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 17MOSFET Summary
Trang 18ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
LOAD-LINE ANALYSIS OF A SIMPLE NMOS AMPLIFIER
( ) t v ( ) t i
R
Trang 19ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 21To establish the load
line, we first locate two points on it.
Trang 22ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 23Amplifier Analysis
Amplifier analysis has two steps:
1 Determine the Q point
2 Use a small-signal equivalent
circuit to determine impedances and gains.
Trang 24ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
The Fixed- Plus Self-Bias Circuit
Trang 25ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 262 1
2
R R
R V
V G DD
+
=
D S GS
( ) 2
to GS
D K v V
Trang 27ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 31SMALL-SIGNAL EQUIVALENT CIRCUITS
( ) t I i ( ) t
( ) t V v ( ) t
v GS = GSQ + gs
Trang 32ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 35ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 36D m
v
i g
D d
v i r
Trang 37ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 39COMMON-SOURCE
AMPLIFIERS
Trang 40ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 41The Small-Signal Equivalent
Circuit
In small-signal midband analysis of FET amplifiers, the coupling capacitors,
bypass capacitors, and dc voltage
sources are replaced by short circuits The FET is replaced with its small-signal equivalent circuit Then, we write circuit equations and derive useful expressions for gains, input impedance, and output impedance.
Trang 42ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Voltage Gain
L D
d
L
R R
r
R
1 1
1
1
+ +
=
′
L m
Trang 43ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Input Resistance
2
1 in
in
i v
R = = G =
Trang 44ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 45Output Resistance
d D
o
r R
R
1 1
1
+
=
To find the output resistance of an
amplifier, we disconnect the load,
replace the signal source by its internal resistance, and then find the resistance looking into the output terminals.
Trang 46ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 48SOURCE FOLLOWERS
Trang 49ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 50The Small-Signal Equivalent
Circuit
Trang 51ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Voltage Gain
L S
d
L
R R
r
R
1 1
1
1
+ +
=
′
L m
L m
o v
R g
R
g v
v A
′ +
Trang 52ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Input Resistance
G
R i
v
R = =
in in in
Trang 53ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 54Output Resistance
d S
m
o
r R
g
R
1 1
1
+ +
=
Trang 55ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Source-Follower Characteristics
The source follower has voltage gain slightly less than unity, high input
impedance, and low output
impedance Current gain and power gain can be larger than unity.
Trang 56ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 59CMOS Inverter
Trang 60ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 61CMOS NAND Gate
Trang 62ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.
Trang 63CMOS NOR Gate
Trang 64ELECTRICAL ENGINEERING: PRINCIPLES AND APPLICATIONS, Third Edition, by Allan R Hambley, ©2005 Pearson Education, Inc.