1. {10%} (a) Use OP to design function: y(t) = Acos(Wit) ; Given x(t) =A, cos(wit) is the input signal. (b) Design a RMS circuit using OP amplifiers to measure rms of x(t). OA, 2. {15%} Given the circuit below (the input resistance of the inverting amplifier can be controlled based on OA1), (a) Find Ri. (b) Let Ri = 10 k 2, R2 = 20 k 2. To obtain Ri = 10 M12, find R3 =? (C) R1 = 10 k 2. specify resistances suitable for achieving A = -10 V/V with R; = 0. = = = R2 2R w = RE Ri R2 Ri OA Ovo
-load amplifier) 3. {15%} (a) What kind is the amplifier of the following circuit? (series/shunt). (b) Find the output impedance of the following. (Hint: List the formula in the form of i. = A ij-V/R.). R₂ R1 14 io L Ro Load + VL a 4. {15%} Given a buck converter whose input voltage is 50 V and output is 25 V, let the switching frequency be 10 kHz and the power output be 125W. Please calculate: (i) the duty cycle, (ii) L value to limit the peak inductor current to 6.25A, (iii) capacitance value to limit the output voltage ripple factor to 0.5%.
R; (=R) 5. {15%) Recalculate the improved Howland circuit if there are two different signals V, and V2. Find io. (no credits count if no detailed derivation). R4 (= R2) w R2B Rza w R2 R2 + R28 Load bio
6. {1596) (a) {(15%)} (a) [Design an alternative bandgap circuit] Isu=/s2=Is (Assuming matched BJTS), prove the following equation. R V =V + KV., where K In) R R (b) Let Is (25°C) = 5x10-15 A for both BJTs, Icı=0.2mA, and R2=10k. Find the values of Ri and R for TC(VREF) = 0 at 25°C. R₂ 11 A. 851 The formula that you might need: forward - bias voltage Vo =V, In – V, D KT thermal voltage V, + 3 9. BT (- V. saturation current Is = Brºexpo-Team TCV, ) = rew)--; ) TCV.=- GO k V-V 3k 9 T 9 k=1.381x10-2.q=1.602x10-19 Vo = 1.205 V
7. {15%} (a) Why do we need a low-dropout (LDO) regulator? (Also, list its advantages) (b) Explain why the power efficiency of switching regulator is better than the linear regulator. (c) Fill the comparison table below for a linear regulator and a switched regulator. Linear Regulator Switched Regulator Which One is Better? Output Range Cost Noise Speed Efficiency Low/High Power Apps
1. {10%} (a) Use OP to design function: y(t) = Acos(Wit) ; Given x(t) =A, cos(wit) is the input signal. (b) Design a RMS
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1. {10%} (a) Use OP to design function: y(t) = Acos(Wit) ; Given x(t) =A, cos(wit) is the input signal. (b) Design a RMS
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