Download ETEE3212 Spring 2007 Test

ETEE3212
Spring 2007
Test #2
Name:________________________
Show all work. Clearly indicate final answer(s).
CHEATSHEET MUST BE TURNED IN WITH TEST OR A ZERO WILL BE
RECEIVED FOR ENTIRE TEST!
1. (40 points) For the Darlington compound
differential amplifier shown to the right,
design the amplifier for a maximum output
voltage swing. Assume VT=26mV, all
individual VBE=0.6V, VBE(Darlington)=1.2V,
all individual β=200, β(Darlington)=20,000,
VA=75V and IEE=1mA. Hint: Assume all
iC=iE. Determine:
a. R1 and RC
b. Undistorted output voltage swing
c. Ad, Ac and CMRR
2. (30 points) Design a single 741 op-amp that will generate vout = 4v1 – 5v2 – 6v3 + 3v4, when
the equivalent resistance at the negative and positive terminals is Req=20kΩ. Determine each
resistor value, input resistance at each of the amplifier inputs and the output resistance. Draw
the schematic and show the resistor values.
3. (30 points) For the emitter-resistor amplifier
to the right, calculate the lower corner 3dB
frequency and sketch the Bode plot
(magnitude
only).
Let
RL=RC=1kΩ,
CC=0.1µF, RE=100Ω, R1=1.5kΩ, R2=10kΩ,
CB=0.01µF, RS=2kΩ, VCC=12V and β=150.
Extra Credit (Maximum 25 points):
Design an op-amp system to measure the output current of a power supply, as shown in the
figure to the right. The voltage across a precision 1W resistor is used to measure the current out
of the power supply. This output current varies from 75mA to 125mA. The digital voltmeter
(DVM) input must be in the range of 0.75v to 1.25V.