An amplifier, whose gain is 80dB ±20 dB, is enclosed in the ideal negative feedback loop of Fig. 5.1 below.
engineering
Description
1. An amplifier, whose gain is 80dB ±20 dB, is enclosed in the ideal negative feedback loop of Fig. 5.1 below. Assuming the feedback factor, Β, may be set with perfect accuracy, what is the largest closed-loop gain that can be realized with better than 1% accuracy?
2. Consider an amplifier with the transfer function ?(?) =
103
(1+
?
104
)(1+
?
107
)
. What is the phase margin
if this amplifier is to be used with feedback to realize a closed-loop amplifier with a gain of 10?
3. The transimpedance amplifier below is driven by a balanced differential input, vin. Assuming all
current sources are ideal and all transistors are in saturation, draw an equivalent small-signal
half circuit and use it to find expressions for each of the following in terms of the transistors’
small-signal parameters, gm, rds , etc
