Thus silicon has an extra electron and will act as a donor impurity.. Thus germanium has one extra electron and will act as a donor impurity.. n-type silicon p-type silicon Si02Photoresi
Trang 2Electronic door bell
Electronic gas pump
Pagers Personal computer Personal planner/organizer (PDA) Radar detector
Broadcast Radio (AM/FM/Shortwave) Razor
Satellite radio receiver Security systems Sewing machine Smoke detector Sprinkler system Stereo system Amplifier
Receiver
Stud sensor Talking toys Telephone Telescope controller Thermostats Toy robots Traffic light controller
TV receiver & remote control Variable speed appliances Blender Drill Mixer
Fan Vending machines Video game controllers Wireless headphones & speakers Wireless thermometer
Workstations Electromechanical Appliances*
Air conditioning and heating systems Clothes washer and dryer
Trang 30.1548= 6.46 years
1.6 F = 8.00x10−0.05806 2020−1970( )μm =10 nm
No, this distance corresponds to the diameter of only a few atoms Also, the wavelength of the
radiation needed to expose such patterns during fabrication is represents a serious problem
1.7
From Fig 1.4, there are approximately 600 million transistors on a complex Pentium IV
microprocessor in 2004 From Prob 1.4, the number of transistors/μP will be 8.85 x 1010
in
2020 Thus there will be the equivalent of 8.85x1010/6x108 = 148 Pentium IV processors
Trang 4A 4 digit readout ranges from 0000 to 9999 and has a resolution of 1 part in 10,000 The
number of bits must satisfy 2B ≥ 10,000 where B is the number of bits Here B = 14 bits
Trang 81.25 The Thévenin equivalent resistance is found using the same approach as Problem 1.24,
Trang 91.26 (a)
R
βi v
Trang 11R
βi v
Trang 136 kHz
Trang 141.41 Band-pass amplifier
f20
v O()t =10x5sin 2000( πt)+10x3cos 8000( πt)+ 0x3cos 15000( πt)
v O()t = 50sin 2000[ ( πt)+ 30cos 8000( πt) ] volts
1.44
v O()t = 20x0.5sin 2500( πt)+ 20x0.75cos 8000( πt)+ 0x0.6cos 12000( πt)
v O()t = 10.0sin 2500[ ( πt)+15.0cos 8000( πt) ] volts
1.45 The gain is zero at each frequency: vo(t) = 0
Trang 17(a)
5V 1( −.05)≤ V ≤ 5V 1+ 05( ) or 5.75V≤ V ≤ 5.25V
V = 5.30 V exceeds the maximum range, so it is out of the specification limits
(b) If the meter is reading 1.5% high, then the actual voltage would be
V meter =1.015V act or Vact = 5.30
1.015= 5.22V which is within specifications limits
Trang 18V2+
V
Trang 201.56 For one set of 200 cases using the equations in Prob 1.53
V =10 * 0.95 + 0.1* RAND()( ) R1= 22000 * 0.9 + 0.2 * RAND()( )
R1= 4700 * 0.9 + 0.2 * RAND()( ) R3 =180000 * 0.9 + 0.2 * RAND()( )
1.57 For one set of 200 cases using the Equations in Prob 1.54:
Trang 21E BT
3
1062.8exp
For silicon, B = 1.08 x 1031 and EG = 1.12 eV:
Trang 22cm A Q
j
2
10/
6 7
sec104
0
cm
MA cm
A x cm cm
C Qv
Trang 23V cm
x
V E
K−3cm−6, k = 8.62x10-5eV/K and EG=1.12eV
This is a transcendental equation and must be solved numerically by iteration Using the HP
solver routine or a spread sheet yields T = 2701 K Note that this temperature is far above the
melting temperature of silicon
Trang 24eV/K and EG=1.12eV
Using MATLAB as in Problem 2.5 yields T = 316.6 K
2.16
Si B
(a) Gallium is from column 3 and silicon is from column 4 Thus silicon has an extra electron
and will act as a donor impurity
(b) Arsenic is from column 5 and silicon is from column 4 Thus silicon is deficient in one
electron and will act as an acceptor impurity
2.18
Since Ge is from column IV, acceptors come from column III and donors come from column
V (a) Acceptors: B, Al, Ga, In, Tl (b) Donors: N, P, As, Sb, Bi
Trang 252.19
(a) Germanium is from column IV and indium is from column III Thus germanium has one
extra electron and will act as a donor impurity
(b) Germanium is from column IV and phosphorus is from column V Thus germanium has
one less electron and will act as an acceptor impurity
cm
A j
22 2
3 14
3 11 3
16 16
16
10502104
1010
4
102210
410105
/cm x
x
p
n | n /cm x
N
N
p
/cm x
n /cm
x x
N : N
N
N
i D
A
i D
Trang 26No, the result is incorrect because of loss of significant digits
within the calculator It does not have enough digits
2.27
(a) Since boron is an acceptor, NA = 6 x 1018/cm3 Assume ND = 0, since it is not specified
The material is p-type
3 3
18
6 20 2
3 18
i 3
18 3
10
7.1610
6
10
and 10
6
So
2n
>>
/106
and10
re, temperatu
room
At
/cm /cm
x
/cm p
n n /cm
x
p
cm x
N N /cm
n
i
D A i
17
6 20 2
3 17
i 3
17 3
10 i
33310
3
10
and 10
3
So
2n
>>
/103
and/
10nre, temperatu
room
At
/cm /cm
x
/cm n
n p /cm
x
n
cm x
N N cm
i
A D
(a) Arsenic is a donor, and boron is an acceptor ND = 2 x 1018/cm3, and NA = 8 x 1018/cm3
Since NA > ND, the material is p-type
Trang 273 3
18
6 20 2
3 18
i 3
18 3
10 i
71610
6
10
and 10
6
So
2n
>>
/106
and/
10nre, temperatu
room
At
(b)
/cm /cm x
/cm p
n n /cm
x
p
cm x
N N cm
i
D A
(a) Phosphorus is a donor, and boron is an acceptor ND = 2 x 1017/cm3, and NA = 5 x 1017/cm3
Since NA > ND, the material is p-type
3 3
17
6 20 2
3 17
i 3
17 3
10
33310
3
10
and 10
3
So
2n
>>
/103
and10
re, temperatu
room
At
(b)
/cm /cm
x
/cm p
n n /cm
x
p
cm x
N N /cm
n
i
D A i
ND = 4 x 1016/cm3 Assume NA = 0, since it is not specified
Trang 29Based upon the value of its resistivity, the material is an insulator However, it is not intrinsic
because it contains impurities Addition of the impurities has increased the resistivity
Trang 302.3 x 10 15 1330 3.06 x 10 18
Trang 31Yes, by adding equal amounts of donor and acceptor impurities the mobilities are reduced, but
the hole and electron concentrations remain unchanged See Problem 2.37 for example
However, it is physically impossible to add exactly equal amounts of the two impurities
Trang 32To change the resistivity to 0.25 ohm-cm:
Additional acceptor concentration = 1.1x1017- 1.7x1016 = 9.3 x 1016/cm3
(b) If donors are added:
So ND = 4.1 x 1016/cm3 must be added to change achieve a resistivity of 0.25 ohm-cm The
silicon is converted to n-type material
Trang 35An n-type ion implantation step could be used to form the n+ region following step (f) in Fig
2.17 A mask would be used to cover up the opening over the p-type region and leave the
opening over the n-type silicon The masking layer for the implantation could just be
photoresist
n-type silicon
p-type silicon
Si02Photoresist
Structure after exposure and
development of photoresist layer
Mask
n-type silicon p-type silicon
Structure following ion implantation of n-type impurity
n +
Ion implantation
Side view
Top View Mask for ion implantation
Trang 3806 -1.003E+04 9.426E-04 9.992E-
16 -1.003E+04
Trang 390.8 0.6
0.4 0.2
Trang 40which is the equation of a straight line with slope 1/nVT and x-axis intercept at -ln (IS) The
values of n and IS can be found from any two points on the line in the figure: e g iD = 10-4 A
for vD = 0.60 V and iD = 10-9 A for vD = 0.20 V Then there are two equations in two
Trang 421.039 7.606E-15
V D I D -Measured I D -Calculated Squared Error
Total Squared Error 1.1622E-06
Trang 44Using trial and error with a spreadsheet yields T = 4.27 K, 14.6 K, and 30.7 K to increase the
saturation current by 2X, 10X, and 100X respectively
Trang 485 anode contacts and 14 cathode contacts
Resistance of anode contacts =10Ω
Trang 49
-1 -2 -3
-4
-5
-6
-1 mA -2 mA (b) Q-point
-1 -2 -3
-4
-5
-6
-1 mA (b) Q-point
iD
(c) Q-point
Trang 50-1 -2 -3 -4
Trang 52The load line equation: V = iD R + vD We need two points to plot the load line
(a) V = 6 V and R = 4kΩ: For vD = 0, iD = 6V/4 kΩ = 1.5 mA and for iD = 0, vD = 6V
Plotting this line on the graph yields the Q-pt: (0.5 V, 1.4 mA)
(b) V = -6 V and R = 3kΩ: For vD = 0, iD = -6V/3 kΩ = -2 mA and for iD = 0, vD = -6V
Plotting this line on the graph yields the Q-pt: (-4 V, -0.67 mA)
(c) V = -3 V and R = 3kΩ: Two points: (0V, -1mA), (-3V, 0mA); Q-pt: (-3 V, 0 mA)
(d) V = +12 V and R = 8kΩ: Two points: (0V, 1.5mA), (4V, 1mA); Q-pt: (0.5 V, 1.4 mA)
(e) V = -25 V and R = 10kΩ: Two points: (0V, -2.5mA), (-5V, -2mA); Q-pt: (-4 V, -2.1 mA)
1 2 3 4 5 6 7 -1
-2 -3 -4 -5
Load line for (b) Q-Point
(-4V,-2.1 mA)
(e)
(c)
Q-Point (-3V,0 mA)
(d)
Q-Point (0.5V,1.45 mA)
Trang 53Using the equations from Table 3.1, (f = 10-10-9 exp , etc.)
VD = 0.7 V requires 12 iterations, VD = 0.5 V requires 22 iterations,
VD = 0.2 V requires 384 iterations - very poor convergence because the second iteration (VD =
1.0000E+00 -9.991E+03 -1.000E+04
9.2766E-04 1.496E-01 -1.003E+04
9.4258E-04 3.199E-06 -1.003E+04
9.4258E-04 9.992E-16 -1.003E+04
9.4258E-04 9.992E-16 -1.003E+04
Trang 54Ideal diode model: ID = 1V/10kΩ = 100μA; (100μA, 0 V)
Constant voltage drop model: ID = (1-0.6)V/10kΩ = 40.0μA; (40.0μA, 0.6 V)
+
-V
I 1 kΩ 1.2 k Ω
1.5 V 1.2 V
0.3 V
+ -
+
-V
I 2.2 k Ω
(a) Ideal diode model: The 0.3 V source appears to be forward biasing the diode, so we will
assume it is "on" Substituting the ideal diode model for the forward region yields
I =
2.2kΩ 0.3V = 0.136 mA This current is greater than zero, which is consistent with the diode
being "on" Thus the Q-pt is (0 V, +0.136 mA)
Ideal Diode:
0.3 V
+ -
+
-V I
2.2 k Ω
CVD:
0.3 V +
-0.6 V
I 2.2 k Ω
+ -
on
V
(b) CVD model: The 0.3 V source appears to be forward biasing the diode so we will assume it
is "on" Substituting the CVD model with Von = 0.6 V yields
I =
2.2kΩ
0.3V − 0.6V = −136 μA
This current is negative which is not consistent with the assumption that the diode is "on"
Thus the diode must be off The resulting Q-pt is: (0 mA, -0.3 V)
0.3 V +
-I=0 2.2 k Ω
- V +
Trang 55(c) The second estimate is more realistic 0.3 V is not sufficient to forward bias the diode into
significant conduction For example, let us assume that IS = 10-15 A, and assume that the full
0.3 V appears across the diode Then
For maximum current, we make the Thévenin equivalent voltage at the diode anode as large as
possible and that at the cathode as small as possible
For minimum current, we make the Thévenin equivalent voltage at the diode anode as small as
possible and that at the cathode as large as possible
Trang 5616kΩ = 0.625 mA (c) Diode is reverse biased : I = 0 | V = −5 +16kΩ I( )= −5 V | VD= −10 V
(d ) Diode is reverse biased : I = 0 | V = 7 −16kΩ I( )= 7 V | VD= −10 V
(c) Diode is reverse biased : I = 0 | V = −5 +16kΩ I( )= −5 V | VD= −10 V
(d ) Diode is reverse biased : I = 0 | V = 7 −16kΩ I( )= 7 V | VD= −10 V
(c) Diode is reverse biased : I = 0 A | V = −5 +100kΩ I( )= −5 V | V D = −10 V
(d ) Diode is reverse biased : I = 0 A | V = 7 −100kΩ I( )= 7 V | V D = −10 V
(b)
Trang 57(c) Diode is reverse biased : I = 0 | V = −5 +100kΩ I( )= −5 V | V D = −10 V
(d ) Diode is reverse biased : I = 0 | V = 7 −100kΩ I( )= 7 V | V D = −10 V
Trang 61MODEL DIODE DIODE DIODE
ID 9.90E-04 -1.92E-12 7.98E-04
VD 7.14E-01 -1.02E+00 7.09E-01
NAME D1 D2 D3
MODEL DIODE DIODE DIODE
ID 4.74E-04 -4.22E-13 2.67E-11
VD 6.95E-01 -4.21E-01 2.63E-01
NAME D1 D2 D3
MODEL DIODE DIODE DIODE
ID 8.79E-03 1.05E-03 7.96E-04
VD 7.11E-01 7.16E-01 7.09E-01
NAME D1 D2 D3
MODEL DIODE DIODE DIODE
ID -4.28E-13 -8.55E-13 1.15E-03
VD -4.27E-01 -8.54E-01 7.18E-01
For all cases, the results are very similar to the hand analysis
Trang 62MODEL DIODE DIODE DIODE
ID 1.47E-03 -4.02E-12 9.35E-04
VD 6.65E-01 -4.01E+00 6.53E-01
The simulation results are very close to those given in Ex 3.8
Trang 63i D -6 -5 -4 -3 -2 -1
Trang 6516.7ms 1ms
Trang 66
(a) V dc = − V( P −V on)= − 6.3 2 −1( )= −7.91V (b) C = I T
V r =7.910.55
10.5
260
+0.000e+000 +10.000m +20.000m +30.000m +40.000m +50.000m +60.000m +70.000m
-10.000 -5.000 +0.000e+000 +5.000 +10.000
SPICE Graph Results: VDC = 9.29 V, Vr = 1.05 V, IP = 811 A, ISC = 1860 A
260
1
1.3ms = 923A
Trang 67V(1) V(2) *REAL(Rectifier)*
Time (s) Circuit3_93b-Transient-11
SPICE Graph Results: VDC = -6.55 V, Vr = 0.58 V, IP = 150 A, ISC = 370 A
Note that a significant difference is caused by the diode series resistance
3.94
(a) V dc = − V( P −V on)= − 6.3 2 −1( )= −7.91V (b) C = I T
V r =7.910.25
10.5
1
400= 0.158F (c) PIV ≥ 2V P = 2 ⋅ 6.3 2 =17.8V (d ) I surge =ωCV P = 2π( )400 (0.158) ( )6.3 2 = 3540 A
2400
194.3μs = 839A
3.95
(a) V dc = − V( P −V on)= − 6.3 2 −1( )= −7.91V (b) C = I T
V r =7.910.25
10.5
2
105
10.377μs = 839A
3.96
Trang 68160
Trang 69The doubler circuit is effectively two half-wave rectifiers connected in series Each capacitor is
discharged by I = 3000V/3000 = 1 A for 1/60 second The ripple voltage on each capacitor is
33.3 V With two capacitors in series, the output ripple should be 66.6 V, which is close to the
Trang 70Simulation Results: VDC = -12.9 V, Vr = 0.20 V, IP = 33.3 A, ISC = 362 A RS results in a
significant reduction in the values of IP and ISC
Trang 71The circuit is behaving like a half-wave rectifier The capacitor should charge during the first
1/2 cycle, but it is not Therefore, diode D1 is not functioning properly It behaves as an open
Trang 7210.25
Trang 733.112
3.3-V, 15-A power supply with Vr ≤ 10 mV Assume Von = 1 V
Filter Capacitor
(i) The large value of C suggests we avoid the half-wave rectifier This will reduce the cost
and size of the circuit
(ii) The PIV ratings are all low and do not indicate a preference for one circuit over another
(iii) The peak current values are lower for the full-wave and full-wave bridge rectifiers and
also indicate an advantage for these circuits
(iv) We must choose between use of a center-tapped transformer (full-wave) or two extra
diodes (bridge) At a current of 15 A, the diodes are not expensive and a four-diode bridge
should be easily found The final choice would be made based upon cost of available
components
3.113
200-V, 3-A power supply with Vr ≤ 4 V Assume Von = 1 V
Filter Capacitor
(i) The the half-wave rectifier requires a larger value of C which may lead to more cost
(ii) The PIV ratings are all low enough that they do not indicate a preference for one circuit
over another
(iii) The peak current values are lower for the full-wave and full-wave bridge rectifiers and
also indicate an advantage for these circuits
(iv) We must choose between use of a center-tapped transformer (full-wave) or two extra
diodes (bridge) At a current of 3 A, the diodes are not expensive and a four-diode bridge
should be easily found The final choice would be made based upon cost of available
components
Trang 743.114
3000-V, 1-A power supply with Vr ≤ 120 V Assume Von = 1 V
Filter Capacitor
(i) A series string of multiple capacitors will normally be required to achieve the voltage
rating
(ii) The PIV ratings are high, and the bridge circuit offers an advantage here
(iii) The peak current values are lower for the full-wave and full-wave bridge rectifiers but
neither is prohibitively large
(iv) We must choose between use of a center-tapped transformer (full wave) or extra diodes
(bridge) With a PIV of 3000 or 6000 volts, multiple diodes may be required to achieve the
require PIV rating