[試題] 電子學(一) 呂良鴻 第三次小考
課程名稱︰電子學(一)
課程性質︰電機系大二上必修
課程教師︰呂良鴻
開課學院：電機資訊學院
開課系所︰電機工程學系
考試日期（年月日）︰2019/12/13
考試時限（分鐘）：50 min
試題 :
1. An NMOS transistor, operating in the linear-resistance region with vds =
50 mV, is found to conduct 25 μA for vgs = 1V and 50μA for vgs = 1.5V.
(a) What is the apparent value of threshold voltage Vt = ? (7%)
(b) If kn'= 50 μA / V^2, what is the device W/L ratio? (7%)
(c) What current would you expect to flow with vgs = 2V and vds = 0.1V? (7%)
(d) If the device is operated at vgs = 2V, at what value of vds will the
drain end of the MOSFET channel just reach pinch-off? And what is the
corresponding drain current? (14%)
2. For each of the circuits shown in Fig.1, find the labeled node voltages. The
NMOS transistors have Vt = 0.9V and kn'(W/L) = 1.5 mA / V^2. (35%, 7% for
each)
+2.5V +5V
↑ ↑
∣ ┌┘
└〢 Q1
└→
｜
├─○V1
｜
┌┘
┌〢 Q2
￣ └→
∣
├─○V2
｜
〈
〉1kΩ
〈
〉
│
↓
-2.5V
+5V
↑
｜
〈
〉1kΩ
〈
〉
│
┌──┼───○V3
｜ │
│ │
｜┌─┘
└〢 Q1
─→
｜
｜
┌──┼───○V4
｜ │
│ │
｜┌─┘
└〢 Q2
─→
｜
｜
├───○V5
│
〈
〉1kΩ
〈
〉
│
｜
￣
Fig.1
3. For the NMOS amplifier in Fig.2, replace the transistor with its T equi-
valent circuit, assuming λ = 0. Derive expressions for the voltage gains
vs/vi and vd/vi. (30%)
+VDD
↑
｜
〈
〉RD
〈
〉
│
├───○ vd
│
┌┘
┌──── 〢
｜ └→
∣ ∣
(±) vi ├───○ vs
∣ ｜
∣ 〈
￣ 〉
〈 RS
〉
│
↓
-VSS
Fig.2
--
A person can only murder another once. The act of murder is giving up
the humanity that is within oneself. What is left is just emptiness. You can not
lose humanity if it is already lost. The act of murder turns into the act of
slaughter. They are two different things.—Ryougi Shiki《A Study in Murder》
https://imgur.com/cq2YDbl
--
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※ 編輯: chun10396974 (140.112.245.134 臺灣), 12/18/2019 17:59:57
推
12/18 21:44,
4年前
, 1F
12/18 21:44, 1F
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※ 編輯: chun10396974 (223.136.223.153 臺灣), 12/19/2019 00:07:39