Summer, 2003 Dr. H. Kaufman Consider the inverter shown in the Figure. A capacitor C = 10pF is connected between the output and ground. Let V DD = 5V, R = 1k , Ron = 100  and V offset = 0.1V. If at time t =0, V I 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(V OH + V OL ). 1. 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  V = 0.1 V/decade change in current. 2. Five questions Pg. 1 of 3 THE UNIVERSITY OF MICHIGAN - DEARBORN ELECTRICAL AND COMPUTER ENGINEERING DEPT. ECE Electronics ABET Outcomes Test

3. For the common-emitter amplifier shown in the Figure, let V CC = 9V, R 1 = 27k , R 2 = 15k , R E = 1.2k , and R C = 2.2 k . The transistor has  = 100. (a) Calculate the DC bias current I E. (b) Draw the SSAC model for the transistor circuit and calculate any required AC parameters. (c) What is the voltage gain v o /v s (d) What is the input impedance (e) What is the output impedance. (a) Draw the CMOS inverter. (b) What is the required relationship between (W/L) p and (W/L) n for which the transistors Q n and Q p are said to be matched and the CMOS inverter is made to switch at the midpoint of logic swing, (i.e. at V DD /2 ) ? 4. 5.Draw the transfer characteristic for the Class B output stage and circle the region in which “crossover distortion” occurs. Assume that Q n and Q p have collector-emitter saturation values V CENsat and V ECPsat respectively. ECE 311 ABET Outcomes Test Summer 2003 pg. 2 of 3

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 v O. (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? ECE 311 ABET Outcomes Test Summer 2003 pg. 3 of 3 (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”?