milk26364325>試卷(2021/09/15)

# 110 年 - 110 國立臺灣大學_碩士班招生考試_生醫電子與資訊學研究所甲組:應用電子學(含電路學、二極體、電晶體及基本電路、放大器)#101254

【非選題】
1.

1. In Fig. 1, let the op amp be ideal:

【題組】 (a) Please derive the transfer function (7%).

【非選題】
2.【題組】(b) Please sketch a Bode plot for the magnitude response (10%).

【非選題】
3.

2. Assuming that the diodes in the circuits of Fig. 2 are ideal, please find the values of the labeled currents and voltages (8%).

【非選題】
4.

3. Consider the amplifier circuit shown in Fig. 3. The BJT has = 0.7 V, β = 200, Cμ = 0.8 pF, and fr= 600 MHz. The MOSFET has Vt= 1 V, k'WIL =2 mA/V2, and =1 pF.

【題組】

(a) Please determine the amplifier input resistance, and the overall voltage gain. Assume ro of both transistors to be very large (12%).

【非選題】
5.【題組】(b) Consider the circuit at low frequencies. Please find the frequency of the poles due to C1 and C2, and hence estimate the lower 3-dB frequency, fL (10%).

【非選題】
6.【題組】(c) Consider the circuit at higher frequencies. Please use open-circuit time constants to estimate fH (8%).

【非選題】
7.

4. For the current-mirror-loaded differential amplifier in Fig. 4. Assume β = 100, = 0.7 V, IVAI = 60 V, Vt = 0.7 V, and k(WI) = 2 mA/V2. Please find:
(a) differential input resistance (5%), (b) Ad (5%), and (c) CMRR (5%).

【非選題】
8.

5. The capacitors of Fig. 5 are uncharged. The switch is closed at t = 0 s for 8 ms.

【題組】 (a) Please determine Vc and ic during charge (4%).

【非選題】
9.【題組】(b) Through the charging process, are the capacitors in steady state? Please explain it 4(%).

【非選題】
10.【題組】(c) Please find the magnitude of the charge and energy stored on the 10- and 40-uF capacitors at t - 8 ms, respectively (4%). After 8 ms, the switch is opened.

【非選題】
11.【題組】(d) Please find Vc and ic during discharge (4%).

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12.【題組】(e) Please estimate how long will the transient last. (4%)

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13.

6. In Fig. 6, please find ZL for maximum average power transfer and please compute the maximum average power supplied to the load. (10%)