Transcript OutcomesTestS03 - University of Michigan

THE UNIVERSITY OF MICHIGAN - DEARBORN
ELECTRICAL AND COMPUTER ENGINEERING DEPT.
ECE 311 - Electronics
ABET Outcomes Test
Summer, 2003
Dr. H. Kaufman
Five questions
Pg. 1 of 3
Consider the inverter shown in the Figure. A capacitor C = 10pF is connected between the
output and ground. Let VDD = 5V, R = 1kW , Ron = 100W and Voffset = 0.1V. If at time
t =0, VI goes low and neglecting the delay time of the switch, that is, assuming it opens
immediately, find the time for the output to reach 0.5(VOH + VOL).
1.
2.
Design the circuit in the Figure to provide an output voltage of 2.4 volts. Assume that the
diodes available have 0.7 volt drop at 1mA and that DV = 0.1 V/decade change in current.
ECE 311 ABET Outcomes Test Summer 2003
pg. 2 of 3
3. For the common-emitter amplifier shown in the Figure, let VCC = 9V, R1 = 27kW ,
R2 = 15kW , RE = 1.2kW , and RC = 2.2 kW . The transistor has b = 100.
(a) Calculate the DC bias current IE.
(b) Draw the SSAC model for the transistor circuit and calculate any required AC
parameters.
(c) What is the voltage gain vo/vs
(d) What is the input impedance
(e) What is the output impedance.
4.
5.
(a) Draw the CMOS inverter.
(b) What is the required relationship between (W/L)p and (W/L)n for which the transistors
Qn and Qp are said to be matched and the CMOS inverter is made to switch at the
midpoint of logic swing, (i.e. at VDD/2 ) ?
Draw the transfer characteristic for the Class B output stage and circle the region in
which “crossover distortion” occurs.
Assume that Qn and Qp have collector-emitter saturation values VCENsat and VECPsat
respectively.
ECE 311 ABET Outcomes Test Summer 2003
pg. 3 of 3
6. The circuit shown in the Figure is intended to supply current to floating loads (those for which
both terminals are ungrounded) while making the greatest possible use of the available power
supply.
(a) Assuming ideal op amps, sketch the voltage waveforms at nodes B and C for a 1-V
peak –to-peak sine wave applied at A. Also sketch vO.
(b) Assuming that the op amps operate from + 15V power supplies and their output saturates
at + 14 V, what is the largest sine wave output (peak to peak value) that can be
accommodated?
+
+
(c) Give at least four characteristics of an ideal op-amp
(Hint: what is open loop gain, output resistance, bandwidth, current into each input?
(d) What is meant by the term “slew rate”?