Filter Capacitor 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 b
Trang 1Electronic 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 20.1548= 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 3A 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 71.25 The Thévenin equivalent resistance is found using the same approach as Problem 1.24,
Trang 81.26 (a)
R
βi v
Trang 10R
βi v
Trang 126 kHz
Trang 131.41 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 16(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 17V2+
V
Trang 191.56 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 20E BT
3
1062.8exp
For silicon, B = 1.08 x 1031 and EG = 1.12 eV:
Trang 21cm A Q
j
2
10/
6 7
sec104
0
cm
MA cm
A x cm cm
C Qv
Trang 22V 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 23eV/K and EG=1.12eV
Using MATLAB as in Problem 2.5 yields T = 316.6 K
2.16
Si B
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 24A 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 25No, 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
Trang 263 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 292.3 x 10 15 1330 3.06 x 10 18
Trang 31To 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:
Trang 34n-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 3706 -1.003E+04 9.426E-04 9.992E-
16 -1.003E+04
Trang 380.8 0.6
0.4 0.2
Trang 411.039 7.606E-15
V D I D -Measured I D -Calculated Squared Error
Total Squared Error 1.1622E-06
Trang 475 anode contacts and 14 cathode contacts
Resistance of anode contacts =10Ω
Trang 48
-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 49-1 -2 -3 -4
Trang 51The 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 52Using 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 = 9.9988 V) is very bad
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 53Ideal 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=0 2.2 k Ω
- V +
Trang 54(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
Trang 5516kΩ = 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 56(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 60MODEL 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 61MODEL 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 62i D -6 -5 -4 -3 -2 -1
Trang 6416.7ms 1ms
Trang 65
(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
2601
1.3ms = 923A
Trang 66SPICE 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 67160
Trang 69Simulation 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 7110.25
Trang 723.112
3.3-V, 15-A power supply with Vr ≤ 10 mV Assume Von = 1 V
Filter Capacitor
(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 733.114
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
Trang 74For this case, simulation yields S = 3 ns
*Problem 3.145(b) - Diode Switching Delay
Trang 75In case (a), the charge in the diode does not have time to reach the steady-state value given by Q
= (1mA)(50ns) = 50 pC At most, only 1mA(7.5ns) = 7.5 pC can be stored in the diode Thus is turns off more rapidly than predicted by the storage time formula It should turn off in approximately t = 7.5pC/3mA = 2.5 ns which agrees with the simulation results In (b), the diode charge has had time to reach its steady-state value Eq (3.103) gives: (50 ns) ln (1-1mA/(-3mA)) = 14.4 ns which is close to the simulation result
3.119
I C =1−10−15
exp 40V( )C −1[ ] A | For V C = 0, I SC =1A
(b) For ISC, the external currents cannot exceed the smallest of the short circuit current
of the individual diodes Thus, I SC = min 1.05A,1.00A,0.95A[ ]= 0.95 A
Note that diode three will be reversed biased in part (b)
Using the computer to find VC yields VC = 0.7768 V, IC = 0.9688 A, and Pmax = 7.53 Watts
Trang 76cm2 | C ox
" = 69.1nF
cm2
50nm 20nm= 691nF
V2 | K n
' = 34.5μA
V2
50nm 5nm = 345μA
Trang 78+0.2 V I
D G
S B
D G
S
B
+
V
Trang 794.14
K n = K n'W
L a( ) W = K n
K n' L= 4mA / V2100μA / V2(0.5μm)= 20 μm b( ) W = 800μA / V2
100μA / V2(0.5μm)= 4 μm
4.15
Trang 80( ) V GS −V TN = 3 -1 = 2V and V DS = 3.3 | V DS > V( GS −V TN) so the saturation region is correct
Trang 81VGS = 2 - (-0.5) = 2.5 V, VGS - VTN = 2.5 - 1 = 1.5 V, and VDS = 0.5 V > triode region
(f) The source and drain of the transistor are again reversed because of the sign change in VDS Assuming the voltages are defined relative to the original S and D terminals as in Fig P4.11(b),
VGS = 3 - (-6) = 9 V, VGS - VTN = 9 - 1 = 8.0 V, and VDS = 6 V > triode region
Trang 82(e) The source and drain of the transistor are now reversed because of the sign change in VDS
Assuming the voltages are defined relative to the original S and D terminals as in Fig 4.54(b),
VGS = 2 - (-0.5) = 2.5 V, VGS - VTN = 2.5 – 0.7 = 1.8 V, and VDS = 0.5 V > triode region
(f) The source and drain of the transistor are again reversed because of the sign change in VDS
Assuming the voltages are defined relative to the original S and D terminals as in Fig 4.54(b),
VGS = 3 - (-3) = 6 V, VGS - VTN = 6 – 0.7 = 5.3 V, and VDS = 3 V > triode region
D
S B G
D G S B
B D
G
Trang 83VDS = 3.3V, VGS – VTN = 1.3 V; VDS > VGS - VTN so the transistor is saturated
Trang 84Starting with the solution from part (a) and solving iteratively yields VGS = 1.20772 V and ID =
108 μA, essentially no change
Starting with the solution from part (a) and solving iteratively yields VGS = 1.3925 V and IDS =
212 μA, essentially no change
4.33
(a) Since VDS = VGS and VTN > 0 for both transistors, both devices are saturated
Trang 85I = I D1 = I D 2 or K n
'
2
101
'
2
W L
Trang 86I = I D1 = I D 2 or K n
'
2
251
μA
V2
251
'
2
W L
Since VDS = VGS, and VTN < 0 for an NMOS depletion mode device, VGS - VTN will be greater
than VDS and the transistor will be operating in the triode region
Trang 87G S
Trang 88(d) In this circuit, the drain and source terminals of the transistor are reversed because of the
power supply voltage, and the current direction is also reversed However, now VDS = VGS and
since the transistor is a depletion-mode device, it is still operating in the triode region
4.40 See figures in previous problem but use W/L = 20/1
(a) If the transistor were saturated, then I D =25x10−6
2
201
= 250 μA but this would require
a power supply of greater than 25 V Thus the transistor must be operating in the triode region
10V −V DS
−6 201
(b) In this circuit, the drain and source terminals of the transistor are reversed because of the
power supply voltage, and the current direction is also reversed However, now VDS = VGS and
since the transistor is a depletion-mode device, it is still operating in the triode region