Chapter 10 Problem Solutions 10.1
a.
( )
( )
1 21 2
2 2 3
23
1 2
2
3 1 2
0 2
2
2 2
1 2 2
BE C
BE C
C BE
V VI I
R RV I R V I R
RV V V V I RR R
RI V V V VR R R
γ
γ
γ γ
γ γ
−
−
−
− −= =
++ = +
+ − − = ++
⎧ ⎫⎛ ⎞⎪ ⎪= − + −⎨ ⎬⎜ ⎟+⎪ ⎪⎝ ⎠⎩ ⎭
b.
( )1 2
3
3
and 1 12 2
2
or 2
BE
C BE
C
V V R R
I V V V VR
VIR
γ
γ γ−
−
= =
⎧ ⎫= − + −⎨ ⎬⎩ ⎭
−=
c. ( )
( ) ( )
33
1 2 1 2 1 21 2
102 mA = 2.5 kΩ
22 0.7 10
2 mA 4.3 kΩ 2.15 kΩ
CI RR
I I R R R RR R
− −= ⇒ =
− − −= = = ⇒ + = ⇒ = =
+
10.2
(a) 11 ln C
BE TS
IV V
I⎛ ⎞
= ⎜ ⎟⎝ ⎠
(i) ( )6
1 1 14
10 1010 A, 0.026 ln 0.5388 V10
10 A
REF C BE
O
I I V
I
μ
μ
−
−
⎛ ⎞×= = = =⎜ ⎟⎝ ⎠
=
(ii) ( )6
1 1 14
100 10100 A, 0.026 ln 0.5987 V10
100 A
REF C BE
O
I I V
I
μ
μ
−
−
⎛ ⎞×= = = =⎜ ⎟⎝ ⎠
=
(iii) ( )3
1 1 14
101 , 0.026 ln 0.6585 V10
1 mA
REF C BE
O
I I mA V
I
−
−
⎛ ⎞= = = =⎜ ⎟
⎝ ⎠=
(b) 21
REFO
II
β
=+
(i)
( )
1 2
6
14
10 9.615 A ln21
509.615 100.026 ln
100.5378 V
OO O BE BE T
S
II I V V V
Iμ
−
−
⎛ ⎞= ⇒ = = = ⎜ ⎟
⎝ ⎠+
⎛ ⎞×= ⎜ ⎟⎝ ⎠
=
(ii) ( )6
1 14
100 96.15 1096.15 A 0.026 ln2 101
500.5977 V
O O BEI I Vμ−
−
⎛ ⎞×= ⇒ = = ⎜ ⎟⎝ ⎠+
=
(iii) ( )3
1 14
1 0.9615 100.9615 mA 0.026 ln2 101
500.6575 V
O O BEI I V−
−
⎛ ⎞×= ⇒ = = ⎜ ⎟⎝ ⎠+
=
10.3
( ) ( )1 1
1
1 2 1 2
1 2
on 3 0.7 30.250
21.2 K
0.250 0.2419 mA2 21 1
604.03 A
BEREF
REFC C C C
B B
V V VI
R RR
II I I I
I Iβ
μ
+ −− − − − −= ⇒ =
=
= = = ⇒ = =+ +
= =
10.4
( ) ( )
( )
1
1 2 1 2
1 2
on 5 0.7 518.3
0.5082 mA0.5082 0.4958 mA
2 21 180
6.198 A
BEREF
REF
REFC C C C
B B
V V VI
RI
II I I I
I Iβ
μ
+ −− − − − −= =
=
= = = ⇒ = =+ +
= =
10.5
(a) ( ) ( )
1 11
15 0.7 15 or 58.6
0.5BE
REF
V V on VI R R k
R
+ −− − − − −= = ⇒ = Ω
(b) ( ) ( )
1 1
0 0.7 1528.6
0.5BE
REF
V V on VR R k
I
+ −− − − − −= = ⇒ = Ω
Advantage: Requires smaller resistance. (c) For part (a):
( ) ( )( )
( ) ( )( )
29.3max 0.526 58.6 0.95
29.3min 0.476 58.6 1.05
0.526 0.476 0.05 5%
O
O
O
I mA
I mA
I mA
= =
= =
Δ = − = ⇒ ±
For part (b):
( ) ( )( )
( ) ( )( )
14.3max 0.526 28.6 0.95
14.3min 0.476 28.6 1.05
0.05 5%
O
O
O
I mA
I mA
I mA
= =
= =
Δ = ⇒ ±
10.6
a. 0
1 1
2 21 2 1 or 2.04 mA100
15 0.7 7.01 kΩ2.04
REF REFI I I
R R
β⎛ ⎞ ⎛ ⎞= + = + =⎜ ⎟ ⎜ ⎟
⎝ ⎠⎝ ⎠−= ⇒ =
b.
( )
00
00
0
0 0
0 0
80 40 kΩ2
1 1 9.3 0.2325 mA40
0.2325 11.6%2
A
CE
VrI
I IV rI I
I I
= = =
Δ ⎛ ⎞= ⇒ Δ = =⎜ ⎟Δ ⎝ ⎠Δ Δ
= ⇒ =
10.7
0 1
1 01 1 2 1
1 1
00
1 11 1
11 or 11
C
CREF C B B C
REF C C
REF
I nII II I I I I
n nI I I
I nIn In n
β β
β β β
ββ
=
= + + = + +
⎛ ⎞ ⎛ ⎞+= + + = +⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠⎛ ⎞+= + =⎜ ⎟ ⎛ ⎞+⎝ ⎠ +⎜ ⎟
⎝ ⎠
10.8
( )
1 1
20.20 1 0.210 mA2 401
5 0.7 4.3 20.5 K0.21
REFO REF
REF
II I
R RI
β
⎛ ⎞= ⇒ = + =⎜ ⎟⎝ ⎠+
−= = ⇒ =
10.9
a.
0 0
5 0.7 0.239 mA18
0.239 0.230 mA21
50
REFI
I I
−= =
= ⇒ =+
b.
( )
00
0 00
50 218 kΩ0.230
1 1 1.3 0.00597 mA 0.236 mA217
A
EC
VrI
I V Ir
= = =
⎛ ⎞Δ = ⋅ Δ = = ⇒ =⎜ ⎟⎝ ⎠
c. ( )0 01 3.3 0.01516 mA 0.245 mA
217I I⎛ ⎞Δ = = ⇒ =⎜ ⎟
⎝ ⎠
10.10
a. ( )
11
5 0.7 51 9.3 kΩREFI R
R− − −
= = ⇒ =
b. 0 02 2 mAREFI I I= ⇒ =
c. ( )2 2 25 0.7For min 0.7 2.15 kΩ
2EC C CV R R−= ⇒ = ⇒ =
10.11
1 1
0.50 mA 0.25 mA
3 31 0.25 160
0.2625 mA2.5 0.7 6.86 K0.2625
O OA OB
REF OA
REF
I I I
I I
I
R R
β
= ⇒ = =
⎛ ⎞ ⎛ ⎞= + = +⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
=−= ⇒ =
10.12
110 0.7 37.2 K
0.25R −= =
10.13
2 1 3 12 and I 3I I I= = (a) 2 31.0 , 1.5 I mA I mA= = (b) 1 30.25 , 0.75 I mA I mA= = (c) 1 20.167 , 0.333 I mA I mA= = 10.14 a.
( ) ( )
( ) ( )
( )
( )
30 1 1 3 1
13 1 2
2 2
11
2
02
20
and 1
2
21 1
211 1
1
211
EC REF C B C
CBE BEE B B
C BEREF C
BEREF
BEREF
II I I I I I
IV VI I IR R
I VI IR
VI IR
VIR
I
β
β
β β β
β β β
β
β β
= = + = ++
= + + = +
= + ++ +
⎛ ⎞− = +⎜ ⎟⎜ ⎟+ +⎝ ⎠
−+
=⎛ ⎞
+⎜ ⎟⎜ ⎟+⎝ ⎠
b. ( ) ( )( ) ( )( )
( )1
1
2 0.70.70 180 81 81 10
0.700216 0.00086410 2 0.7
0.7011 mA 12.27 kΩ
REF
REF
REF
I
I
I RR
⎛ ⎞= + +⎜ ⎟⎜ ⎟
⎝ ⎠= +
−= = ⇒ =
10.15 a.
( )( )
0
1 2
and 1
... 11
ESi CR REF CR BS CR
ES BR B B BN BR
CR
II I I I I I
I I I I I N IN I
β
β
= = + = ++
= + + + + = ++
=
( )( )
( )( )
0
1Then
1
or 1
11
CRREF CR
REFi
N II I
IIN
β β
β β
+= +
+
=⎛ ⎞+
+⎜ ⎟⎜ ⎟+⎝ ⎠
b. ( ) ( )( )( ) ( )
1 1
60.5 1 0.5012 mA50 51
5 2 0.7 517.16 kΩ
0.5012
REFI
R R
⎡ ⎤= + =⎢ ⎥
⎢ ⎥⎣ ⎦− − −
= ⇒ =
10.16
( ) ( ) ( )( )( ) ( )
0
1 1
2 21 0.5 1 0.5004 mA1 50 51
5 2 0.7 517.19 kΩ
0.5004
REF REFI I I
R R
β β⎛ ⎞ ⎡ ⎤
= + = + ⇒ =⎜ ⎟ ⎢ ⎥⎜ ⎟+ ⎢ ⎥⎝ ⎠ ⎣ ⎦− − −
= ⇒ =
10.17
( )
( ) ( )( )
0
0
1 1
121
2
For 0.8 mA
20.8 1 0.8024 mA25 27
18 2 0.720.69 kΩ
0.8024
REF
REF REF
I I
I
I I
R R
β β
= ⋅⎛ ⎞
+⎜ ⎟⎜ ⎟+⎝ ⎠=
⎛ ⎞= + ⇒ =⎜ ⎟⎜ ⎟
⎝ ⎠−
= ⇒ =
10.18
The analysis is exactly the same as in the text. We have
( )
01
212
REFI I
β β
= ⋅⎛ ⎞
+⎜ ⎟⎜ ⎟+⎝ ⎠
10.19
( )
0 2
1 1
3 1 2
33
1 3
1 1
22 mA, 0.0267 mA7511 mA, 0.0133 mA75
0.0133 0.0267 0.04 mA0.04 0.000526 mA
1 761.000526 1 mA
10 2 0.7 8.6 8.6 kΩ1
B
C B
E B B
EB
REF C B REF
REF
I I
I I
I I III
I I I I
R RI
β
= = =
= = =
= + = + =
= = =+
= + ⇒ = ≈
−= = ⇒ =
10.20 (a)
( )( )
3
3
Assuming 2100 400 K0.25
100 40020 M
2
oO
A AO
O REF
O O
rR
V VrI I
R R
β≈
= = = =
= ⇒ = Ω
(b) 5
20 M 20 M0.25 A
O OO
O
V VR II
I μ
Δ Δ= ⇒ Δ = =Δ Ω Ω
Δ =
10.21
1
1
5 0.79.3
0.4624 mA
0.026 0.4624ln ln1.5
0.46240.01733ln
BEREF
REF
T REFO
E O O
OO
V V VIR
I
V IIR I I
II
+ −− − −= =
=
⎛ ⎞ ⎛ ⎞= =⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠⎛ ⎞
= ⎜ ⎟⎝ ⎠
By trial and error
( )( )2
2
2
41.7 A0.70.7 0.0417 1.50.6375 V
O
BE O E
BE
BE
IV I RVV
μ= −= −=
10.22 (a)
( )
( )
1
1
3
5 0.7 593
100
93 10 ln 10 0.026ln
BEREF REF
REFO E T O
O O
V V VI I AR
I mAI R V II I
μ+ −
−
− − −− −= = ⇒ =
⎛ ⎞ ⎛ ⎞×= ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
By trial and error, 6.8OI Aμ≅
( )2 21o o m ER r g R′= + Now
( )( )
2
2
2
30 4.41 6.80.0068 0.2615 /0.026100 0.026
382.4 0.0068π
= = Ω
= =
= = Ω
o
m
r M
g mA V
r k
So 2 || 382 ||10 9.74 E ER r R kπ′ = = = Ω
Then ( )( )4.41 1 0.262 9.74 15.6 = + ⇒ = Ω⎡ ⎤⎣ ⎦o oR R M
(b) ( )( )1 2 1 20.0068 10 0.068 − = = ⇒ − =BE BE o E BE BEV V I R V V V 10.23
( )
( )( )
( ) ( )( )
00
0 02 2
020
02
2
2
0
180 11.76 M6.80.0068 0.2615 mA/V0.026
80 0.026306 k
0.006810 306 9.68 K
11.76 1 0.2615 9.68 41.54 M
C
m E
A
mT
E E
II VR
R r g RVrII
gV
r
R R rR
π
π
Δ = ⋅ Δ
′= +
= = = Ω
= = =
= = Ω
′ = = == + = Ω⎡ ⎤⎣ ⎦
Now
( )0 01 5 0.120 A
41.54I I μ⎛ ⎞Δ = ⇒ Δ =⎜ ⎟
⎝ ⎠
10.24
(a) ( )
1
1
5 0.7 50.50
18.6 K
ln
0.026 0.50ln0.050 0.0501.20 K
REF
REFO E T
O
E
E
IR
R
II R VI
R
R
− − −= =
=
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞= ⎜ ⎟⎝ ⎠
=
(b) [ ]
( )( )
( )( ) ( )
2 2
2
2 2
2
1
75 0.026 0.05039 K 1.923 mA/V0.050 0.026
100 2 M 1.20 39 1.164 K0.05
2 1 1.164 1.923 6.477 M
O c E m
E E
m
Ao E
O
O O
R r R gR R r
r g
Vr RI
R R
π
π
′= +′ =
= = = =
′= = ⇒ Ω = =
= + ⇒ = Ω⎡ ⎤⎣ ⎦
(c) 5 0.772 A6.477
0.772100% 100 1.54%50
OO
O
O
VIR
II
μΔΔ = = =
Δ× = × =
10.25 Let 1 5 ,= ΩR k Then
( )12 0.7 124.66
5− − −
= ⇒ =REF REFI I mA
Now 0.026 4.66ln ln 1 0.10 0.10
REFO E T E E
O
II R V R R kI
⎛ ⎞ ⎛ ⎞= ⇒ = ⇒ ≅ Ω⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
10.26
( )
( )
315
3
15
1 1
0 0
ln
100.7 0.026 ln 2.03 10 A
2 10At 2 mA, 0.026 ln2.03 10
0.718 V15 0.718 7.14 kΩ
20.026 2ln ln 1.92 k0.050 0.050
REFBE T
S
SS
BE
T REFE E
IV VI
II
V
R R
V IR RI I
−−
−
−
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⇒ = ×⎜ ⎟⎝ ⎠
⎛ ⎞×= ⎜ ⎟×⎝ ⎠=
−= ⇒ =
⎛ ⎞ ⎛ ⎞= = ⋅ ⇒ = Ω⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
10.27 a.
10 0.7 0.465 mA20
Let 0
REFI
V −
−≈ =
=
( )3
15
ln
100.7 0.026 ln 2.03 10 A
REFBE T
S
SS
IV VI
II
−−
⎛ ⎞≅ ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⇒ = ×⎜ ⎟⎝ ⎠
Then
( )3
15
0.465 100.026 ln 0.680 V2.03 10
−
−
⎛ ⎞×≅ =⎜ ⎟×⎝ ⎠BEV
Then
10 0.680 0.466 mA20
−≅ ⇒ =REF REFI I
b. 0 0
0.026 0.466ln 4000.10 0.10
lnT REFE E
V IR RI I
⎛ ⎞ ⎛ ⎞= = ⇒ = Ω⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
⋅
10.28
( )
( )3
15
10 0.7 100.4825 mA
40
ln
100.7 0.026 ln 2.03 10 A
REF
REFBE T
S
SS
I
IV VI
II
−−
− − −≈ =
⎛ ⎞≅ ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⇒ = ×⎜ ⎟⎝ ⎠
( )3
15
1
Now
0.4825 100.026 ln 0.681 V2.03 10
0.681 V
BE
BE
V
V
−
−
⎛ ⎞×= =⎜ ⎟×⎝ ⎠=
( )
( ) ( )
00
00
So10 0.681 10
0.483 mA40
ln
0.48312 0.026 ln
REF REF
REFE T
I I
II R VI
II
− − −≅ ⇒ =
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⎜ ⎟⎝ ⎠
( )( )0
2 1 0 2
By trial and error.8.7 A
0.681 0.0087 12 0.5766 VBE BE E BE
I
V V I R V
μ⇒ ≅
= − = − ⇒ =
10.29
1 1 2 0 2
1 2 0 2 1
BE REF E BE E
BE BE E REF E
V I R V I RV V I R I R
+ = +− = −
For matched transistors
1
02
0 2 10
ln
ln
Then ln
REFBE T
S
BE TS
REFT E REF E
IV VI
IV VI
IV I R I RI
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⎜ ⎟⎝ ⎠⎛ ⎞
= −⎜ ⎟⎝ ⎠
Output resistance looking into the collector of Q2 is increased. 10.30
(a) ( )1
1 1
5 0.7 50.3174 mA
27.3 20.3174 mA
BEREF
E
O REF
V V VIR R
I I
+ − − − −− −= = =+ +
= =
(b) Using the same relation as for the widlar current source.
( )2 2 2
2 2
1
80 0.3174252 K 12.21 mA/V0.3174 0.026
O o m E
Ao m
O
R r g R r
Vr gI
π⎡ ⎤= +⎣ ⎦
= = = = =
( )( )
( )( )2 2
100 0.0268.192 K || 2 || 8.192 1.608 K
0.3174252 1 12.21 1.608 5.2 M
E
O O
r R r
R R
π π= = = =
= + ⇒ = Ω⎡ ⎤⎣ ⎦
(c) ( )
2
5 0.7 50.3407 mA
27.380 235 K
0.3407
O REF
AO o O
O
I I
VR r RI
− − −= = =
= = = ⇒ =
10.31 Assume all transistors are matched. a.
1 3 0
1
03
2
ln
ln
BE BE E
REFBE T
S
BE TS
V V I R
IV VI
IV VI
= +
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞
= ⎜ ⎟⎝ ⎠
00
2
00
2
00
2 ln ln
ln ln
ln
REFT T E
S S
REFT E
S S
REFT E
S
IIV V I RI I
IIV I RI I
IV I RI I
⎛ ⎞ ⎛ ⎞− =⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠⎡ ⎤⎛ ⎞ ⎛ ⎞⎢ ⎥− =⎜ ⎟ ⎜ ⎟⎢ ⎥⎝ ⎠ ⎝ ⎠⎣ ⎦⎛ ⎞
=⎜ ⎟⎝ ⎠
b.
( )
3 15
3
15
0 0
0.70.7 V at 1 mA 10 exp or 2.03 10 A0.026
0.1 10 at 0.1 mA 0.026 ln 0.640 V2.03 10
0.640Since , then or 6.4 k0.1
BE S S
BE BE
REF BE E E E
V I I
V V
I I V I R R R
− −
−
−
⎛ ⎞= ⇒ = = ×⎜ ⎟⎝ ⎠
⎛ ⎞×⇒ = =⎜ ⎟×⎝ ⎠
= = ⇒ = = Ω
10.32 (a)
( )1
1
2 2
3 2
5 0.7 50.80 mA
11.6 K
0.026 0.80ln 1.44 K0.050 0.0500.026 0.80ln 4.80 K0.020 0.020
REF
E E
E E
IR
R
R R
R R
− − −= =
=
⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠
(b) ( )( )( )( )
2 2
3 3
0.7 0.05 1.44 0.628 V0.7 0.02 4.80 0.604 V
BE BE
BE BE
V VV V
= − ⇒ == − ⇒ =
10.33 (a)
1 2
1
1 2
1 2 3
1 3 2
1 3
2
Now2or
2
We have
ln and ln
BE BE
BEREF
BE REF BE O E
O E BE BE REF
OREFBE T BE T
S S
V VV V VI
R R
V I R V I R
I R V V I R
IIV V V VI I
+ −
=− −=
+
+ = +
= − +
⎛ ⎞ ⎛ ⎞= =⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠
(b) Let 1 2R R= and 1 3O REF BE BE BEI I V V V= ⇒ = ≡
( )
( )
2 2
2
2
2 2
Then
so22
2Then
2
BE O E REF O E
O EREF O
EO O
O
V I R I R I R R
V V I R RI I
R
RV V I IR R
V VIRε
+ −
+ −
+ −
= − = −
− − −= =
⎛ ⎞−= − +⎜ ⎟⎝ ⎠
−=
(c) Want 0.5 OI mA=
( )( )
( ) ( )2
5 5So 10
2 0.5
5 2 0.7 52 17.2
0.5
E ER R k
R k
− −= ⇒ = Ω
− − −= = Ω
1 2Then 8.6 R R k= = Ω 10.34 a.
01
02
03
20 0.7 0.7 1.55 mA12
2 3.1 mA1.55 mA
3 4.65 mA
REF
REF
REF
REF
I
I II II I
− −= =
= == == =
b. ( ) ( )( )
( )( )( )( )
1 01 1 1
2 02 2 2
3 03 3 3
10 3.1 2 10 3.8 V
10 10 1.55 3 5.35 V
10 10 4.65 1 5.35 V
CE C CE
EC C EC
EC C EC
V I R V
V I R V
V I R V
= − − − = − + ⇒ =
= − = − ⇒ =
= − = − ⇒ =
10.35 a. Ist approximation
( )
20 1.4 2.325 mA8
2.32Now 0.7 0.026 ln 0.722 V1
REF
BE BE EB
I
V V V
−≅ =
⎛ ⎞− = ⇒ = =⎜ ⎟⎝ ⎠
Then 2nd approximation ( )
01
02
03
20 2 0.7222.32 mA
82 4.64 mA
2.32 mA3 6.96 mA
REF
REF
REF
REF
I
I II II I
−≅ =
= == == =
b.
( )1 1
2 2
3 3
At the edge of saturation,0.722 V
0 0.722 102.0 k
4.6410 0.722 4.0 k
2.3210 0.722 1.33 k
6.96
CE BE
C C
C C
C C
V V
R R
R R
R R
= =− − −
= ⇒ = Ω
−= ⇒ = Ω
−= ⇒ = Ω
10.36
( )
( )
1 2
3 4
55
10 0.7 0.7 101.86 mA
101.86 mA
1.860.5 0.026ln
C C
C C
CC
I I
I I
II
− − − −= = =
= =
⎛ ⎞= ⎜ ⎟
⎝ ⎠
By Trial and error. 5 6 70.136 mAC C CI I I⇒ = = =
( ) ( )( )3 3 3
3
2 0.8 10 10 2 1.86 0.87.02 V
C CE CE
CE
I V VV
+ = ⇒ = −=
( )( )( )
6 5 5
5
5
5 0.5 105 10 0.7 0.136 0.514.2 V
EB CE C
CE
CE
V V IVV
= + + −= + − −=
( )( )( )
7 7
7
7
5 0.85 0.136 0.84.89 V
EC C
EC
EC
V IVV
= += −=
10.37
( )
( )
1 2 1 2
4 5
13 1 3
3 3
10 0.7 0.7 101.86 mA
101.86 mA
1.86ln 0.3 0.026ln
C C C C
C C
CC E T C
C C
I I I I
I I
II R V I
I I
− − − −= = ⇒ = =
= =
⎛ ⎞ ⎛ ⎞= ⇒ =⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠
By trial and error 3 0.195 mACI =
( )56 2 6
6 6
1.86ln 0.5 0.026lnCC E T C
C C
II R V I
I I⎛ ⎞ ⎛ ⎞
= ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
By trial and error 6 0.136 mACI =
10.38
( )( )( )
10 0.7 1 mA6.3 3
0.7 V as assumed1 3 3 V
REF
BE R
RER REF ER
I
V QV I R
−= =+
== ⋅ = =
11 1 1
01
22 2 2
02
33 3 3
03
33 V 3 k133 V 1.5 k233 V 0.75 k4
= ⇒ = = ⇒ = Ω
= ⇒ = = ⇒ = Ω
= ⇒ = = ⇒ = Ω
RERE E E
RERE E E
RERE E E
VV R RI
VV R RI
VV R RI
01
02
03
1 mA2 mA4 mA
===
III
10.38
( )
( )
( ) ( )
( )
( ) ( )
2 2 2 2 2
22 2
2
2
2 2
2 11
2
2 1
3
2 1.5 3.5 12
250 20 3.5 1.5 3.125
12
100 20 3.5 1.5 1.25
Now 10
DS GS TN GS GS
O n ox GS TN
REF n ox GS TN
GS
V sat V V V V V VWI C V VL
W WL L
WI C V VL
W WL L
V
μ
μ
= = − = − ⇒ =
⎛ ⎞⎛ ⎞= −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
⎛ ⎞⎛ ⎞= −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
=
( ) ( )2
2
3 3
10 3.5 6.5
So 100 20 6.5 1.5 0.2
GSV VW WL L
− = − =
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.39
( )( )
( )
2
2
2
2.5 0.08 6 0.515 2
2.5 3.6 0.25
3.6 2.6 1.6 0
GSREF GS
GS GS GS
GS GS
VI V
V V V
V V
− ⎛ ⎞= = −⎜ ⎟⎝ ⎠
− = − +
− − =
( )( )
( )
2.6 6.76 23.042 3.6
1.12 V 1.11932.5 1.1193 92.0 A 92.05
1592.0 A
GS
GS
REF REF
o
V
V
I I
I
μ
μ
± +=
=−= ⇒ =
=
( )( )
2
2
sat 1.1193 0.5sat 0.619 V
DS GS TN
DS
V V VV
= − = −=
10.39 a. From Equation (10.50),
( ) ( )
( ) ( )
( ) ( )( )( )
1 2
1 22 2
1 1
5 5125 255 0.5
5 51 125 25
0.447 1 0.4475 0.51 0.447 1 0.447
1.74 V
18 25 1.74 0.5 0.692
GS GS
GS GS
REF n GS TN REF
V V
V V
I K V V I mA
⎛ ⎞ ⎛ ⎞−⎜ ⎟ ⎜ ⎟
⎜ ⎟ ⎜ ⎟= = +⎜ ⎟ ⎜ ⎟
+ +⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
−⎛ ⎞ ⎛ ⎞= +⎜ ⎟ ⎜ ⎟+ +⎝ ⎠ ⎝ ⎠= =
≅ − = − ⇒ =
b. ( ) ( )
( )( )( ) ( )( )( )( )
22 2
22
0
0
1 12
18 15 1.74 0.5 1 0.02 2
415 104 0.432 mA
O n ox GS TN DSWI C V V VL
I
I
μ λ⎛ ⎞⎛ ⎞= − +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
= − +⎡ ⎤⎣ ⎦= ⇒ =
c. ( ) ( )( )0 0415 1 0.02 4 0.448 mAI I= + ⇒ =⎡ ⎤⎣ ⎦ 10.40 (a)
( )2
1
8050 0.52
2.00.050
REF GS
GSREF
WI VLV
IR
⎛ ⎞⎛ ⎞= = −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
−= =
Design such that ( )2 sat 0.25 0.5DS GSV V= = − 0.75 VGSV =
So 2 0.750.050 25 KRR
−= ⇒ =
( )2
1 1
1
2
2 2
8050 0.75 0.5 202
20 50 40100
REF
O
W WL L
WIL W
W WI LL L
⎛ ⎞⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
⎛ ⎞⎜ ⎟ ⎛ ⎞⎝ ⎠ = ⇒ = ⇒ =⎜ ⎟⎛ ⎞ ⎛ ⎞ ⎝ ⎠⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
(b) ( )( )
1 1 667 K0.015 0.1O O
O
R RIλ
= = ⇒ =
(c) 1 1.5 A666
1.5100% 100% 1.5%100
OO
O
O
VIR
II
μΔΔ = = ⇒
Δ ⎛ ⎞× = × ⇒⎜ ⎟⎝ ⎠
10.41
(a) ( )( )
( )( )
2
2
80250 3 12
2.44 V250 A at 2.44 V
1 1 200 K0.02 0.25
REF GS
GS
O DS GS
OO
I V
VI V V
RI
μ
λ
⎛ ⎞= = −⎜ ⎟⎝ ⎠
== = =
= = =
(i) 3 2.44 2.8 A200
252.8 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
(ii) 4.5 2.44 10.3 A200
260.3 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
(iii) 6 2.44 17.8 A200
267.8 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
(b) ( )
( )( )
4.5 250 375 A at 2.44 V31 1 133.3 K
0.02 0.375
O DS
OO
I V
RI
μ
λ
= = =
= = =
(i) 3 2.44 4.20 A133.3
379.2 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
(ii) 4.5 2.44 15.5 A133.3
390.5 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
(iii) 6 2.44 26.7 A133.3
401.7 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
10.41
( )
( )
( )
2 2
22
2
2
2 2
0.25 0.4 0.65
24025 0.65 0.4 202
SD SG TP SG SG
pO SG TP
V sat V V V V Vk WI V V
LW WL L
= = + = − ⇒ =′ ⎛ ⎞= +⎜ ⎟⎝ ⎠
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
( )( )
( )
( )
1
12
23
3
3
2
3 3
75 60
23 0.65 2.35
40Then 75 2.35 0.4 0.9862
REF O
pREF SG TP
SG
W L WI A IW L L
k WI V VL
V VW WL L
μ/ ⎛ ⎞= = ⋅ ⇒ =⎜ ⎟/ ⎝ ⎠
′ ⎛ ⎞= +⎜ ⎟⎝ ⎠
= − =
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.42 (a)
11
2
2 21 1
0.51 2 0.5
REFGS TN
n
REF REFO n n
n n
IV V VK
I II K KK K
= + = + =
⎛ ⎞ ⎛ ⎞= =⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎝ ⎠⎝ ⎠
( ) ( )( ) ( )
( ) ( )( ) ( )
0 0
0 0
0.5max 0.5 1.05 max 0.525 mA0.50.5min 0.5 0.95 min 0.475 mA0.5
I I
I I
⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠
0So 0.475 0.525 mAI≤ ≤ (b)
( ) ( )
( ) ( )
2
2 1 21
2
0 0
2
0 0
0.5min 0.5 1 1.05 (min) 0.451 mA0.5
0.5max 0.5 1 0.95 (max) 0.551 mA0.5
REFO n TN TN
n
II K V VK
I I
I I
⎡ ⎤= + −⎢ ⎥
⎢ ⎥⎣ ⎦
⎡ ⎤= + − ⇒ =⎢ ⎥
⎣ ⎦
⎡ ⎤= + − ⇒ =⎢ ⎥
⎣ ⎦
0So 0.451 0.551 mAI≤ ≤ 10.43
(1) 2x A
x m gso
V VI g V
r−
= +
(2) 1
1 2,
Ax m gs
o
gs x gs A
VI g Vr
V V V V
= +
= = −
So
(1) 1xx A m
o o
VI V g
r r⎛ ⎞
= − +⎜ ⎟⎝ ⎠
(2) [ ]Ax m x A o x m x
o
VI g V V r I g Vr
= + ⇒ = −
( )
[ ]
2
2
2
Then
1
12
xx o x m x m
o o
x x mx o m x x m x
o o o
xx x m o x m x m o x
o
x m o x m m oo
VI r I g V gr r
V I gI r g I V g V
r r rVI I g r I g V g r Vr
I g r V g g rr
⎛ ⎞= − − +⎜ ⎟
⎝ ⎠⎡ ⎤
= − + − ⋅ −⎢ ⎥⎣ ⎦
= − − + +
⎡ ⎤+ = + +⎢ ⎥
⎣ ⎦
Since 1m
o
gr
>>
[ ] ( )( )2 1x m o x m m oI g r V g g r+ ≅ +
( )2
Then 1
x m oo
x m m o
V g rR
I g g r+
= =+
Usually, 2,m og r >> so that 1o
m
Rg
≅
10.44
( )
( )
( )
2 2 2
2
2 2
1 1
1
2
3
2
3 3
(sat) 2 0.8 2.8 V60200 2.8 0.8 1.672
0.4 3.330.2 1.67
6 2.8 3.2 V60400 3.2 0.8 2.312
DS GS GS
O
REF
O
GS
REF
V V VW WIL L
W WI L L W
WI LL
VW WIL L
= = − ⇒ =
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟ ⎛ ⎞⎝ ⎠ ⎝ ⎠= ⇒ = ⇒ =⎜ ⎟⎛ ⎞ ⎝ ⎠⎜ ⎟⎝ ⎠
= − =
⎛ ⎞⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
10.45 (a)
( )( ) ( )( )
( )
( )( )
( )( )
2 21 3
1 3
1 1
1 1 2
22
2
60 6020 0.7 3 0.72 2
5
20 0.7 5 0.73
3.582 6.107 1.705 V60 12 1.705 0.7 363.6 A at 1.705 V260 20 1.705 0.7 606 A2
REF GS GS
GS GS
GS GS
GS GS GS
O DS
REF
I V V
V V
V V
V V V
I V
I
μ
μ
⎛ ⎞ ⎛ ⎞= − = −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
+ =
− = − −
= ⇒ = =
⎛ ⎞= − = =⎜ ⎟⎝ ⎠⎛ ⎞= − =⎜ ⎟⎝ ⎠
(b) ( )( )
1 1 183.4 K0.015 0.3636
1.5 1.705 1.12 A183.4
362.5 A
OO
OO
O
RIVI
RI
λ
μ
μ
= = =
Δ −Δ = = ⇒ −
=
(c) 3 1.705 7.06 A183.4
370.7 A
OO
O
VIR
I
μ
μ
Δ −Δ = = ⇒
=
10.46
( )( ) ( )( )
( )
( )( )
2 21 3
1 3 3 1
1 1
1 1
2
2 2
50 5015 0.5 3 0.52 2
10 10
15 0.5 10 0.53
3.236 10.618 3.28 V50 15 3.28 0.5 2.90 mA2
2.90 mA(sat) 3.28 0.5
REF SG SG
SG SG SG SG
SG SG
SG SG
REF REF
O REF
SD SG TP
I V V
V V V V
V V
V V
I I
I IV V V
⎛ ⎞ ⎛ ⎞= − = −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
+ = ⇒ = −
− = − −
= ⇒ =
⎛ ⎞= − ⇒ =⎜ ⎟⎝ ⎠
= == + = − 2 (sat) 2.78 VSDV⇒ =
10.47
( )
( )( )
( )
( )
2 2 2
2
2 2
1 1
12
1 3 3
2
3 3
(sat) 1.2 0.35 1.55 V50100 1.55 0.35 2.782
200 5.56100 2.78
4 2.45 V50200 2.45 0.35 12
SD SG SG
O
REF
O
SG SG SG
REF
V V VW WIL L
W WI WL L
WI LL
V V VW WIL L
= = − ⇒ =
⎛ ⎞⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
⎛ ⎞= ⇒ = ⇒ =⎜ ⎟⎝ ⎠
+ = ⇒ =
⎛ ⎞⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
.81
10.48
( )( ) ( )( )
( )
( )( )
( )
2 21 3
11 3 3
11
1 1
2
2 2 2
80 8025 1.2 4 1.22 2
102 102
1025Then 1.2 1.24 2
3 6.8 2.27 V80 25 2.267 1.2 1.14 mA2
(sat) 2.27 1.2 sat
REF SG SG
SGSG SG SG
SGSG
SG SG
REF REF O
SD SG TP SD
I V V
VV V V
VV
V V
I I I
V V V V
⎛ ⎞ ⎛ ⎞= − = −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
−+ = ⇒ =
−− = −
= ⇒ =
⎛ ⎞= − ⇒ = =⎜ ⎟⎝ ⎠
= + = − ⇒ = 1.07 V
10.49
( )
( )( )( )
2 2 2
2
2 2
1
2
1
1
(sat) 1.8 1.4 3.2 V80 3.2 1.4 100 0.7722
200 1.54100 0.772
SD SG SG
O
REF
O
V V VW WIL L
WI L
WIL
WWLL
= = − ⇒ =
⎛ ⎞⎛ ⎞ ⎛ ⎞= − = ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
=
⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠
Assume M3 and M4 are matched.
( )
3 1 3
2
3,4
3,4
10 3.22 10 3.4 V2
80200 3.4 1.42
1.25
SG SG SG
REF
V V V
WIL
WL
−+ = ⇒ = =
⎛ ⎞⎛ ⎞= = −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ =⎜ ⎟⎝ ⎠
10.50 (a)
( )
( )
21
1
23
3
2
2
pREF SG TP
pSG TP
k WI V VL
k W V VL
′⎛ ⎞⎛ ⎞= +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
′⎛ ⎞⎛ ⎞= +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
( ) ( )3 1
2 21 1
1
3
But 3
So 25 0.4 5 3 0.4which yields 1.08
and 1.92
SG SG
SG SG
SG
SG
V V
V VV V
V V
= −
− = − −=
=
( )( )( )( )
( )( )
2
2
1
20 25 1.08 0.4 231
/ 15 0.6/ 25
Then 0.6 231 139
REF REF
O
REF
O
I I A
W LII W L
I A
μ
μ
= − ⇒ =
= = =
= =
(b) ( )2 1.08 0.4 0.68 3 0.68 2.32
then2.32 16.7
0.139
DS
R O
V sat VV I R
R R k
= − == − = =
= ⇒ = Ω
10.51
( ) ( )
( )( )
( ) ( )
( ) ( )
2 2 2
2
2 2
1 1
1
2
3
2
3 3
(sat) 0.35 0.4 0.75 V
80 20 0.75 0.4 32.7
50 20.480 32.7
3 0.75 2.25
50 20 2.25 0.4 0.730
SD SG SG
O
REF
O
SG
REF
V V VW WIL L
W WI L L W
LWIL
VW WIL L
= = − ⇒ =
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
= ⇒ = ⇒ =
= − =
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.52 a. ( )
( )
2
2
4 0
100 100 2 3 VFor 3 V, 100 A
REF n GS TN
GS GS
D
I K V V
V VV I μ
= −
= − ⇒ == − =
b. ( )
( )( )( ) ( )( )
( )( )
0 04 02 04
02 040
0
0
0 4 00
11 1 500 k
0.02 0.12 2 0.1 3 2 0.2 /500 500 1 0.2 500
51 M1 6 0.118 A
51
m
m n GS TN
D
R r r g r
r rI
g K V V mA VR
R
I V IR
λ
μ
= + +
= = = = Ω
= − = − == + +⎡ ⎤⎣ ⎦= Ω
Δ = ⋅ Δ = ⇒ Δ =
10.53
( )( )
( )
4 02
6 4 04 02
02 04 02
6 02 02 04 61
= −
= − +
= + += + + = −⎡ ⎤⎣ ⎦
gs X
S X m gs X
X m X X
S X m gs
V I r
V I g V r I r
I g I r r I rV I r g r r V
( )
66 6
06 06 06
02 02 0406 06
1
1 1
⎛ ⎞−= + = − +⎜ ⎟
⎝ ⎠⎛ ⎞
= − + + +⎡ ⎤⎜ ⎟ ⎣ ⎦⎝ ⎠
X S XX m gs S m
XX X m m
V V VI g V V gr r r
VI I g r g r rr r
( )
( ) ( )
( )
( ) ( )( )
( )( )
02 02 0406 06
0 06 06 02 02 04
20
02 04 060
11 1
1 1
0.2 mA 0.2 12 V2 2 0.2 2 1 0.4 /
1 1 250 k0.02 0.2λ
⎧ ⎫⎛ ⎞⎪ ⎪+ + + + =⎡ ⎤⎨ ⎬⎜ ⎟ ⎣ ⎦⎪ ⎪⎝ ⎠⎩ ⎭
= = + + + +⎡ ⎤⎣ ⎦
≈ = = −== − = − =
= = = = = Ω
XX m m
Xm m
X
REF GS
GS
m n GS TN
VI g r g r rr r
V R r g r r g r rI
I I VVg K V V mA V
r r rI
( )( ) ( )( ) ( ) 0
90 0
250 1 0.4 250 250 1 0.4 250 250
2575750 k 2.58 10
= + + × + +⎡ ⎤ ⎡ ⎤⎣ ⎦ ⎣ ⎦= Ω ⇒ = × Ω
R
R R
10.54
( ) ( )
( )
2 21 3
1 3
24
4
2 2
2
n nGS TN GS TN
pGS TP
k kW WV V V VL L
k W V VL
′ ′⎛ ⎞ ⎛ ⎞− = −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
′ ⎛ ⎞= +⎜ ⎟⎝ ⎠
(1) ( )( ) ( )( )2 21 350 20 0.5 50 5 0.5GS GSV V− = −
(2) ( )( ) ( )( )2 21 450 20 0.5 20 10 0.5GS GSV V− = −
(3) 4 3 1 6SG GS GSV V V+ + =
From (1) ( ) ( ) ( )2 21 3 3 14 0.5 0.5 2 0.5 0.5GS GS GS GSV V V V− = − ⇒ = − +
From (2) ( ) ( ) ( )2 21 4 4 15 0.5 0.5 5 0.5 0.5− = − ⇒ = − +GS GS SG GSV V V V
Then (3) becomes ( ) ( )1 1 1
1 3 4
5 0.5 0.5 2 0.5 0.5 6which yields 1.36 and 2.22 , 2.42
GS GS GS
GS GS SG
V V VV V V V V V
− + + − + + == = =
( ) ( )( )
( ) ( )
2 21
1
1 2
2 2 2
Then 50 20 1.36 0.5 or 0.740 2
1.36 1.36 0.5 0.86
nREF GS TN REF O
GS GS
DS GS TN DS
k WI V V I I mAL
V V VV sat V V V sat V
′ ⎛ ⎞= − = − = =⎜ ⎟⎝ ⎠
= == − = − ⇒ =
10.55
( )
( )
( )
2 2 2 2
22
2
2
2 2
0.5 0.5 1
50 2
50 1 0.5 4
DS GS TN GS GS
nO GS TN
V sat V V V V V V
k WI A V VL
W WL L
μ
= = − = − ⇒ =′ ⎛ ⎞= = −⎜ ⎟⎝ ⎠
⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
( ) ( )2 21 2 1
1 1 1
1 150 50 1 0.5 122′ ⎛ ⎞ ⎛ ⎞ ⎛ ⎞= = ⇒ = = − = − ⇒ =⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠ ⎝ ⎠
nGS GS REF GS TN
k W W WV V V I V VL L L
3 4 1
3 3
62 6 1 5 2.5
GS SG GS
GS GS
V V VV V V V
+ + == − = ⇒ =
( )
( )
( )
2
3 3
24
4
2
4 4
150 50 2.5 0.5 0.75
2
150 20 2.5 0.5 1.88
REF
pREF SG TP
W WIL L
k WI V VL
W WL L
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
′ ⎛ ⎞= +⎜ ⎟⎝ ⎠
⎛ ⎞ ⎛ ⎞= − ⇒⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.56 a. As a first approximation
( )( )
21 1
1
80 80 1 2 VThen 2 2 4 V
REF GS GS
DS
I V VV
= = − ⇒ =≅ =
The second approximation ( ) ( )( )
( )
21
21 1
80 80 1 1 0.02 4
80Or 1 1.96286.4
GS
GS GS
V
V V
= − +⎡ ⎤⎣ ⎦
= − ⇒ =
( ) ( )( ) ( )( )
21 1
2
0
Then
1
80 1.962 1 1 0.02 1.962
Or 76.94 A
O n GS TN n GSI K V V V
I
λ
μ
= − +
= − +⎡ ⎤⎣ ⎦=
b. From a PSpice analysis, 0 77.09 Aμ=I for 3 1 VDV = − and 0 77.14 Aμ=I for 3 3 V.DV = The change is 0 0.05 A or 0.065%.I μΔ ≈ 10.57 a. For a first approximation,
( )24 480 80 1 2 VREF GS GSI V V= = − ⇒ =
As a second approximation ( ) ( )( )
( ) ( )
24
4 12
2 2
80 80 1 1 0.02 2
Or 1.98 V
1
REF GS
GS GS
O n GS TN GS
I V
V V
I K V V Vλ
= = − +⎡ ⎤⎣ ⎦= =
= − +
To a very good approximation 0 80 Aμ=I b. From a PSpice analysis, 0 80.00 Aμ=I for 3 1 VDV = − and the output resistance is
0 76.9 M .= ΩR Then
0 30
0
For 3 V1 4 0.052 A
76.980.05 A
D
D
V
I VR
I
μ
μ
= +
Δ = ⋅ = =
=
10.58 (a) ( ) ( )
( )
( )
3 3 3 3
23
2
3
or 0.2 0.8 1.0
2
50 48 0.2 26
DS GS TN GS DS TN
nD GS TN
V sat V V V V sat Vk WI V V
LW WL L
= − = + = + =′ ⎛ ⎞= −⎜ ⎟⎝ ⎠⎛ ⎞ ⎛ ⎞= ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
(b) ( )( )
5 3
5 5
20.8 2 0.2 1.2
GS TN GS TN
GS GS
V V V VV V V
− = −= + ⇒ =
(c) ( ) ( ) ( ) ( )1 1min 2 2 0.2 min 0.4 D DS DV V sat V V= = ⇒ =
10.59 (a)
( )
( )( )
( )( )( )( )
21
1
1
1 1 2
50 5 250 /2
/1 1/
1 51 8.944 0.6838500.25 0.05
6.12
nn
n D
k WK A VL
W LR
W LK I
R k
μ′ ⎛ ⎞= = =⎜ ⎟⎝ ⎠
⎛ ⎞⎜ ⎟= −⎜ ⎟⎝ ⎠
⎛ ⎞= − =⎜ ⎟⎜ ⎟
⎝ ⎠= Ω
(b)
( )( )
( )( )( )
( )( )( )
3 1
3 32
1 3 3
32
1 1 1
min
50 20 5 0.5 1.207 Then 1.21 0.5 0.707
Also 50 50 5 0.5 0.9472
Then 0.71 0.947 1.66
SD GS
SD SG TP
D SG SG
SD
D GS GS
V V V sat VV sat V V
I V V VV sat V
I V V V
V V V
+ −
+ −
− = += +
= = − ⇒ == − =
= = − ⇒ =
− = + =
(c)
( )
( )
21
5 5
22
6 6
25 50 0.947 0.5 2.5
75 20 1.207 0.5 7.5
O
O
W WIL L
W WIL L
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
⎛ ⎞ ⎛ ⎞= = − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.60
( )
( )
( ) ( )
( )
3
23
3
2
3 3 4 5
21 3
1
3
01
1
01
1
1 5 1.667 V3
12
100 20 1.667 1 11.25
12
Or
GS
REF n ox GS TN
O n ox GS TN
REF
REF
V
WI C V VL
W W W WL L L L
WI C V VL
WI L
WIL
IW WL I L
μ
μ
= =
⎛ ⎞⎛ ⎞= −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞ ⎛ ⎞ ⎛ ⎞= − ⇒ = = =⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠ ⎝ ⎠ ⎝ ⎠
⎛ ⎞⎛ ⎞= −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞⎜ ⎟⎝ ⎠=⎛ ⎞⎜ ⎟⎝ ⎠
⎛ ⎞⎛ ⎞ = ⎜ ⎟⎜ ⎟⎝ ⎠ ⎝ ⎠
( )
( )
3 1
02
2 3 2
0.2 11.25 22.50.1
0.3And 11.25 33.750.1REF
WL
IW W WL I L L
⎛ ⎞ ⎛ ⎞ ⎛ ⎞= ⇒ =⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠ ⎝ ⎠
⎛ ⎞⎛ ⎞ ⎛ ⎞ ⎛ ⎞ ⎛ ⎞= = ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠ ⎝ ⎠ ⎝ ⎠⎝ ⎠
10.61
( )( )( )( )
( ) ( )
( )
2
2
24
Also 40 1 1.2
18 1 1.2
Then 40 1.2 18 1.26.325which yields 1.2 1.24.243
SGP GSNREF
REF GSN
REF SGP
GSN SGP
SGP GSN
V VIR
I V
I V
V V
V V
− −=
= −
= −
− = −
= − +
( ) ( )
( )( )( )( )
( )
2
1
2
3
4
Then 0.040 1.2 24 1.49 1.2 1.2
which yields 2.69 and 3.43
24 3.42 2.69Now 89.4 200
89.4 17.9 5
1.25 89.4 112 0.8 89.4 71.5
4 89.4 358
GSN GSN GSN
GSN
SGP
REF REF
V R V V
V VV V
I I A
I A
I AI AI A
μ
μ
μμ
μ
⎡ ⎤− ⋅ = − − − −⎣ ⎦=
=− −= ⇒ =
= =
= == == =
10.61 a. ( )
( ) ( )( ) ( )
( )( )
( )( )
0
0 0
0 0
0 0
2
2 0.25 0.2 0.447 mA/V
1 1 250 k0.02 0.2
1 1 167 k0.03 0.2
m n REF
m m
n nn REF
p pp REF
g M K I
g M g M
r rI
r rI
λ
λ
=
= ⇒ =
= = ⇒ = Ω
= = ⇒ = Ω
b. ( ) ( )( )0 0|| 0.447 250 ||167 44.8v m n p vA g r r A= − = − ⇒ = −
c. 0 0205 ||167 || or 100 kL n p LR r r R= = = Ω 10.62
( )( )( )( )( )( )
( )
1
2
3
4
We have 2.69 and 3.43 10 2.69 3.43 3.88So 19.4
200Then 0.2 19.4 3.88
1.25 19.4 24.3 0.8 19.4 15.5
4 19.4 77.6
GSN SGP
REF REF
V V V V
I I AR
I AI AI AI A
μ
μμ
μμ
= =− −= = ⇒ =
= == == == =
10.63
( )( ) ( )
( )( ) ( )
( )( )
( )
22 2
1
42
3
24
4
4 4
9 200 120 A15
20 120 267 A9
40266.7 20 0.62
1.416 V(sat) 1.416 0.6 sat 0.816 V
D REF D
O D O
O SG
SG
SD SD
WLI I I
WL
WLI I I
WL
I V
VV V
μ
μ
= ⋅ = ⇒ =
⎛ ⎞= ⋅ = ⇒ =⎜ ⎟⎝ ⎠
⎛ ⎞= = −⎜ ⎟⎝ ⎠
== − ⇒ =
10.64
( )21
1
1
4050 0.62
1.7550
REF SG
SGREF
WI VL
VI
R
⎛ ⎞⎛ ⎞= = −⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠−
= =
( )
2 2 2
2
1 1
(sat) 0.35 0.6 0.95 V1.75 0.95 16 K
0.054050 0.95 0.6 20.42
SD SG SGV V V
R R
W WL L
= = − ⇒ =−= ⇒ =
⎛ ⎞⎛ ⎞ ⎛ ⎞= − ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
( )( )
( )( )
1 2
2
3 3
3
120 4950 20.4
25 10.250 20.4
O
REF
D
REF
WI WLI L
WI WLI L
⎛ ⎞= = ⇒ =⎜ ⎟⎝ ⎠
⎛ ⎞= = ⇒ =⎜ ⎟⎝ ⎠
( )
( )
5 5 5
22
5 5
34 4
42 2
(sat) 0.35 0.4 0.75 V100 0.75 0.4 150 24.5
2
25 4.08150 24.5
DS GS GS
O
DD
O O
V V VW WIL L
WII WL
I I L
= = − ⇒ =
⎛ ⎞⎛ ⎞ ⎛ ⎞= − = ⇒ =⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠ ⎝ ⎠
⎛ ⎞= = = ⇒ =⎜ ⎟⎝ ⎠
10.65 For ( )0, 1GS D DSS DSv i I vλ= = + a.
( ) ( )( )5 V, 52 1 0.05 5 2.5 mA
D DS
D D
V vi i
= − == + ⇒ =⎡ ⎤⎣ ⎦
b. ( ) ( )( )0, 102 1 0.05 10 3 mA
D DS
D D
V vi i
= == + ⇒ =⎡ ⎤⎣ ⎦
c. ( ) ( )( )5 V, 15 V2 1 0.05 15 3.5 mA
D DS
D D
V vi i
= == + ⇒ =⎡ ⎤⎣ ⎦
10.66
( )( )
( )
2
0
2
0
0
1
2 4 1
21 0.2934
So 0.293 4 1.17 V
Then and
1.170.586 k
2
⎛ ⎞= −⎜ ⎟
⎝ ⎠
⎛ ⎞= −⎜ ⎟
⎝ ⎠
= − =
= − = −
= = −
−−= = − ⇒ = Ω
GSDSS
P
GS
P
GS
P
GS
SS GS
GS
VI IV
VV
VV
VVI V VR
VR R
I
Finish solution: See solution 10.66 Completion of solution
( )( )
( )
Need sat1.17 4
2.83 VSo sat 2.83 1.17 4 V
DS DS GS P
DS
D DS S D
v v v V
vV v V V
≥ = −= − − −
≥≥ + = + ⇒ ≥
10.67
a.
( )
11
3
1 1131
exp
1 10or ln 0.026 ln 0.55685 10
EBREF S
T
REFEB T EB
S
VI IV
IV V VI
−
−
⎛ ⎞= ⎜ ⎟
⎝ ⎠⎛ ⎞ ⎛ ⎞×= = ⇒ =⎜ ⎟ ⎜ ⎟×⎝ ⎠⎝ ⎠
b. 1 15 0.5568 4.44 k
1R R−= ⇒ = Ω
c. From Equations (10.79) and (10.80) and letting 0 2 2.5 V= =CE ECV V
( )
( )
12 3
12 3
9
2.512.5 8010 exp 1 100.5568120 1
801.031251.0208333 10 exp 101.00696
Then 0.026ln 1.003222 10
So 0.5389
I
T
I
T
I
I
VV
VV
V
V V
− −
− −
⎛ ⎞+⎜ ⎟⎛ ⎞ ⎡ ⎤+ = ⎜ ⎟⎜ ⎟ ⎢ ⎥⎣ ⎦⎝ ⎠ ⎜ ⎟+⎜ ⎟⎝ ⎠
⎛ ⎞ ⎛ ⎞× =⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
= ×
=
d. ( )
( ) ( )1/
1/ 1/1
38.460.0261 1 0.00833 0.0125
120 801846
Tv
AN AP
v
v
VA
V V
A
A
−=
+
− −= =++
= −
10.68
a. ( )3
121
0.5 10ln 0.026 ln 0.520810
REFBE T BE
S
IV V V
I
−
−
⎛ ⎞ ⎛ ⎞×= = ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠⎝ ⎠
b. 1 15 0.5208 8.96 k
0.5R R−= ⇒ = Ω
c. Modify Eqs. 10.79 and 10.80 to apply to pnp and npn, and set the two equation equal to each other.
22 2
13 12
13 12
exp 1 exp 1
2.5 2.55 10 exp 1 10 exp 180 120
5.15625 10 exp 1.020833 10 exp
EBO ECO CEBECO SO C S
T AP T AN
EBO BE
T T
EBO BE
T T
V V VVI I I IV V V V
V VV V
V VV V
− −
− −
⎛ ⎞⎛ ⎞⎛ ⎞ ⎛ ⎞= + = = +⎜ ⎟⎜ ⎟⎜ ⎟ ⎜ ⎟
⎝ ⎠⎝ ⎠ ⎝ ⎠⎝ ⎠⎛ ⎞ ⎛ ⎞⎛ ⎞ ⎛ ⎞× + = +⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠⎝ ⎠ ⎝ ⎠⎛ ⎞ ⎛ ⎞
× = ×⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
( ) ( ) ( )
exp1.9798 exp
exp
ln 1.9798 0.5208 0.026 ln 1.97980.5386 5 0.5386 4.461 V
EBO
T EBO BE
TBE
T
EBO BE T
EBO I I
VV V V
VVV
V V VV V V
⎛ ⎞⎜ ⎟ ⎛ ⎞−⎝ ⎠ = = ⎜ ⎟⎛ ⎞ ⎝ ⎠⎜ ⎟⎝ ⎠= + = += ⇒ = − ⇒ =
d. ( )
( ) ( )1/
1/ 1/1
38.460.0261 1 0.00833 0.0125
120 801846
Tv
AN AP
v
v
VA
V V
A
A
−=
+
− −= =++
= −
10.69 a. M1 and M2 matched. For 0 ,=REFI I we have 2 3 0 2.5 V= = = =SD SG SG DSV V V V For M1 and M3:
( ) ( )
( ) ( )( )
2
1
2
1 1 3 2
1 12
100 10 2.5 1 1 0.02 2.5 4.23
REF p ox SG TP P SDWI C V V VL
W W W WL L L L
μ λ⎛ ⎞⎛ ⎞= + +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞ ⎛ ⎞ ⎛ ⎞= − + ⇒ = = =⎡ ⎤⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎣ ⎦⎝ ⎠ ⎝ ⎠ ⎝ ⎠ ⎝ ⎠
For M0:
( ) ( )
( ) ( )( )
2
0
2
0 0
1 12
100 20 2 1 1 0.02 2.5 4.76
O n ox GS TN n DSWI C V V VL
W WL L
μ λ⎛ ⎞⎛ ⎞= − +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞= − + ⇒ =⎡ ⎤⎜ ⎟ ⎜ ⎟⎣ ⎦⎝ ⎠ ⎝ ⎠
b.
( )( )
( )( )( )
( ) ( )( )
0 00
0 0
1 1 500 k0.02 0.1
12 22
2 0.02 4.76 0.1
0.195 mA/V
|| 0.195 500 || 500 48.8
n p
m n O n ox Oo
m
v m n p v
r rI
Wg K I C IL
g
A g r r A
λ
μ
= = = = Ω
⎛ ⎞⎛ ⎞= = ⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
=
=
= − = − ⇒ = −
10.70 a. ( )
( )
21
2100 100 1 2 VREF p SG TP
SG SG
I K V V
V V
= +
= − ⇒ =
b. From Eq. 10.89 ( ) ( )
( )( )( ) ( )
( )( )
( )
2
2
2
2
1
1 0.02 10 2 100 15
0.02 0.02 100 0.02 0.02
15 29
0.041 0.961.98 V
p SG n I TNO
n p REF n p
I
I
I
I
V V K V VV
I
V
V
VV
λ
λ λ λ λ
+⎡ ⎤+ − −⎣ ⎦= −+ +
+ −⎡ ⎤ −⎣ ⎦= −+ +
−= −
− ==
c. ( )
( )( )( )( )
( )( )
0 0
0 0
||
1 1 500 k0.02 0.1
2 2 0.1 0.1 0.2 /
0.2 500 || 500 50
v m n p
n pREF
m n REF
v v
A g r r
r rI
g K I mA V
A A
λ
= −
= = = = Ω
= = =
= − ⇒ = −
10.71
1
5 0.6 5 0.6 0.22 mA20REFI
R− −= = =
From Eq. 10.96
0.220.026
0.22 1 0.221140 90
8.4615 8.46151 10.0015714 0.002444 0.004016
C
Tv
C C
LAN L AP
L L
IV
AI I
RV R V
R R
⎛ ⎞−⎜ ⎟ −⎝ ⎠= =
⎛ ⎞ + ++ +⎜ ⎟⎝ ⎠
− −= =+ + +
(a) , 2107L vR A= ∞ = − (b) 250 K, 1056L vR A= = − (c) 100 K, 604L vR A= = − 10.72
5 0.6 0.1257 mA35
Then2 0.2514 mA
REF
CO REF
I
I I
−= =
= =
From Eq. 10.96 0.2514
9.66920.0260.2514 0.2514 1 10.002095 0.0031425
120 809.6692
10.0052375
v
L L
v
L
A
R R
A
R
−−= =
+ + + +
−=+
(a) 1846= ∞ = −L vR A (b) 250 K, 1047L vR A= = − 10.73 (a) To a good approximation, output resistance is the same as the widlar current source.
( )0 02 2 21 ||m ER r g r Rπ= +⎡ ⎤⎣ ⎦
(b) ( )0 0 0|| ||v m LA g r R R= − 10.74 Output resistance of Wilson source
( )
( )( ) [ ]
030
0 0
03
0
2Then ||
80 400 k0.2
120 600 k0.2
0.2 7.692 mA/V0.026
80 4007.69 600 7.69 600 ||16,000 4448
2
v m
AP
REF
AN
REF
REFm
T
v v
rR
A g r RVrI
VrIIgV
A A
β≅
= −
= = = Ω
= = = Ω
= = =
⎡ ⎤= − = − ⇒ = −⎢ ⎥
⎢ ⎥⎣ ⎦
10.75 (a) 2 0 200 AD D REFI I I μ= = =
( )( )
( )( )
( )( )
( )( )
2 22
2 2
2
0
1 1For ; 250 K0.02 0.2
0.042 2 35 0.22
0.748 mA/V1 1For ; 333 K
0.015 0.2
0.082 20 0.2 0.80 mA/V2
oP D
m P D
m
n Do
mo mo
M rI
g K I
g
M rI
g g
λ
λ∞
= = =
⎛ ⎞= = ⎜ ⎟⎝ ⎠
=
= = =
⎛ ⎞= ⇒ =⎜ ⎟⎝ ⎠
(b) ( ) ( )( )2 || 0.80 250 || 333114.3
v mo o oo
v
A g r rA
= − = −= −
(c) ( )Want 57.15 0.80 142.8 ||
142.8142.8 || 71.375 143 K142.8
v L
LL L
L
A RRR RR
= − = −
= = ⇒ =+
10.76 Assume M1, M2 matched
( )( )
( )( )( )( )
( )
2
22
0
2
0
0
200 A1 1 250 K
0.02 0.21 1 333 K
0.015 0.2
100 250 333 0.70 mA/V
0.082 0.2 0.702
15.3
REF D Do
op D
oon D
v mo o oo
mo mo
mo
I I I
rI
rI
A g r r
g g
WgL
WL
μ
λ
λ
= = =
= = =
= = =
= −
− = − ⇒ =
⎛ ⎞⎛ ⎞= =⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞ =⎜ ⎟⎝ ⎠
( )
0 2
2
2 1
Now 2 2
80 4015.32 2
30.6
pn kk W WL L
WL
W WL L
′′ ⎛ ⎞⎛ ⎞⎛ ⎞ ⎛ ⎞= ⎜ ⎟⎜ ⎟ ⎜ ⎟⎜ ⎟⎝ ⎠ ⎝ ⎠⎝ ⎠ ⎝ ⎠⎛ ⎞ ⎛ ⎞⎛ ⎞=⎜ ⎟ ⎜ ⎟⎜ ⎟⎝ ⎠ ⎝ ⎠⎝ ⎠
⎛ ⎞ ⎛ ⎞= =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠
10.77
Since 3 0,sgV = the circuit becomes
( )
( )
22 2 3
02
33
2 2
32 3
2
2 3 2
1 1
and
Then
1
so that
1
or1
x sgx m sg sg x o
o xx m o
o o
x oo o m o
x o
o o o m o
ov m o o
i
V VI g V V I r
r
r VI g r
r r
V rR r g rI r
R r r g rvA g r Rv
−′= − + =
⎛ ⎞′+ + =⎜ ⎟⎝ ⎠
⎛ ⎞′= = + +⎜ ⎟⎝ ⎠
′= + +
= = −
( )( )( )
( )( )
1
1
Now
2 0.050 20 0.10 0.632 /
1 1 500 0.02 0.10
m
on DQ
g mA V
r kIλ
= =
= = = Ω
( )( )( )
( )( )2 3
2 2 0.020 80 0.1 0.80 /
1 1 500 0.020 0.1
m p DQ
o op DQ
g K I mA V
r r kIλ
′ = = =
= = = = Ω
( )( )( )( )
Then
500 500 1 0.8 500 201
0.632 500 201000 315o
v v
R M
A A
= + + ⇒ Ω⎡ ⎤⎣ ⎦= − ⇒ = −
10.78 From Eq. 10.105
( ) ( ) ( )
2
3 4 1 2
1
1 1
22
2 0.050 20 0.08
0.5657 /
mv
o o o o
nm D
m
gA
r r r r
k Wg IL
g mA V
−=
+
′⎛ ⎞ ⎛ ⎞= ⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
=
=
( )( )( )
( ) ( )( )
2
2 2
1 1 625 K0.02 0.08
0.5657 0.32001 1 2 0.00000256
625 62562,500
oD
v
v
rI
A
A
λ= = =
− −= =+
= −
10.79
(1) ( )22 2
1 2 22 1 2
Om i m
o o
V VV Vg V g Vr r r
ππ ππ
π
− −= + + +
(2) ( )2
2 23 2
0OOm
O o
V VV g VR r
ππ
− −+ + =
(1) 1 2 22 1 2 2
1 1 1 Om i m
o o o
Vg V V g
r r r rππ
⎛ ⎞= + + + +⎜ ⎟
⎝ ⎠
(2) 2 23 2 2
1 1 1 0O mO o o
V V gR r rπ
⎛ ⎞ ⎛ ⎞+ + + =⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠
1m
o
gr
>>
(1) 1 22 2
1 Om i
o
Vg V V
r rππ
β⎛ ⎞+= +⎜ ⎟⎝ ⎠
(2) 2 23 2
1 1 0O mO o
V V gR r π
⎛ ⎞+ + ⋅ =⎜ ⎟
⎝ ⎠
(3) 22 3 2
1 1O
m O o
VV
g R rπ⎛ ⎞
= − +⎜ ⎟⎝ ⎠
Then
12 3 2 2 2
3 2 2
3
1 3
1 1 1(1)
1 1 1
1
1
O Om i
m O o o
OO
O o o
O
O
Om O
i
V Vg Vg R r r r
VVR r r
VR
V g RV
π
β
ββ
ββ
ββ
⎛ ⎞⎛ ⎞+= − + +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞⎛ ⎞+= − + +⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
⎛ ⎞+≈ − ⎜ ⎟⎝ ⎠⎛ ⎞
= − ⎜ ⎟+⎝ ⎠
From Equation (10.20) 3 3O OR rβ≈ So
( )( )( )
21 3
3
2
0.25 9.615 mA/V1 0.026
80 320 K0.25
9.615 320 120366,165
121
O m ov m
i
o
v
V g rA gV
r
A
ββ
−= = = =
+
= =
−= = −