=========================preview======================
(ELEC304)[2010](s)quiz~716^_60391.pdf
Back to ELEC304 Login to download
======================================================
ECE 304 April 20, 2011
Spring 2011 Howard Luong

Analog Integrated-Circuit Design and Analysis


QUIZ #3
Student ID:
Bodes plots of the open-loop gain A(j.) of an operational amplifier are shown below. Consider applying the amplifier in a feedback configuration with the feedback gain f.
a.
For f = 0.01, what are the phase margin and the gain margin? PM = 45o , GM = -20dB (20 pt.)

b.
For f = 0.01, is the feedback system stable? YES (5 pt.)

c.
What would be the feedback factor f for the system to achieve a phase margin of 90o? 0.001 (10 pt.)


d.
For f = 1 with a narrowbanding compensation, where should the new dominant pole be addded to achieve a PM of 45o. 100 / 104 = 0.01 Hz (15 pt.)

e.
For f = 1 with an improved compensation, where should the original first pole be moved to for a PM of 45o. 10K / 104 = 1 Hz (15 pt.)

f.
For f = 1 with an improved compensation, if the original first pole is moved to 0.5Hz, what would be the PM: 60o (20 pt.), and what would be the new unity-gain frequency? 5KHz (15 pt.)