Page 14 - 電子學含實習

Chapter 7 xږः̒ఙࣖཥ౺᜗ (MOSFET) ׳ɽཥ༩

＋V DD ＋V DD
R D R D
10k Ω 10k Ω C
V o 2 V o

V i 10μF 10 μF i o V i C 1 i i i o
i i R L R L
R G 40 kΩ R G 10 kΩ
400 kΩ R S 5MΩ
1 kΩ 10 μF V GG ＋ Z
Z i Z o Z i 3V － o

༆ (1) Z i = R G = 400kΩ
(2) Z o = R D // R L = (10 // 40) = 8(kΩ) ഈ

(3) ཥ༩މӚϞ R S ཥڜٙ΍๕฽€CS׳ɽኜ
A v = –g m R D ' = –2 × (R D // R L )
= –2 × (10 //40) = –16
i Z 400k
(4) A = i 0 = − A × R i =−16 × 40k = −160
v
i
i
L
€i o ၾ i i ˙Σ޴ˀd݂̋ࠋ໮
ၚ፯ᇍԷ 3 ΝӉᇖ୦ 3

νྡהͪٙ΍๕฽׳ɽཥ༩dண MOSFET ٙ νྡהͪʘ׳ɽཥ༩dண FET ʘʝኬ g =
m
ਞᅰ g = 3mSdϾ R = 3MΩdR = 3MΩdR = 1kΩd 2mΩdϾ r ≈ ∞dۆՉc(1) A = V o
m
S
2
1
i
V i ds v V i c(2) Zc
ۆ Չc(1) A = o c(2) Zc(3) A = o c΢މ
v
V i i i i i i
(3) A = o c΢މОk
i
Оk i i
＋V DD +V DD
R D i
R D 6kΩ o
R 1 3kΩ C 2 V o 20μF V
i i V i 20μF i i C o o
V i R L i o

C 1 6kΩ C i R
R 2 R S R G 100Ω 1

Z i Z o Z i 1.2MΩ R C
S
470Ω 2 2μF
電阻的共源極（CS）放大器，
༆ (1) 電路為有 R S
其電壓增益

gR ' −×(//) 6
3
3
D
m
A ≈− = =− . 15
v
+×1
1 + gR 13 ഈ
mS
// = 3 // 3 = 1.5(MΩ)
(2) Z i = R 1 R 2
i Z 15 .M
(3) A = o = − A × i =−15 . × = −375
v
i
i i R L 6k 9
€i o ၾ i i ˙Σ޴ˀd݂̋ɪࠋ໮