ECE 311 Test #2 April 29, 2005 Honor Code in effect Open book and notes I have neither given nor received aid on this examination. ______________________________ Print your name:___________________________________ Show all work in the allotted space for each problem and circle each answer. No other material will be accepted for test answers. 1. Consider the given circuit with β = β0 = 100, VCC is 15V, and -VCC is -10.7V. a) (10) What is the voltage gain of the circuit if V1=V2 given that R2 = R3 = 5K and R1 = 5K? b) (10) What is VCEQ1? c) (10) How does the CMRR of the circuit vary as –VCC is varied? d) (10) What is the input impedance of the circuit if V1=-V2?2. You are to design a 25 W Class B public address amplifier with one input that will operate off of a pair of batteries of equal voltages and provide a voltage gain of 100. Assume that available op amps have a gain-bandwidth product of 1 MHz and can come within .3V of the rail voltage. A 16-ohm speaker will be used. a) (10) If the upper frequency limit of the amplifier is to be 50 kHz, how many op amps will you need to provide the necessary gain? b) (10) How can the circuit be designed so that the frequency response goes down to DC? c) (10) Draw your circuit showing component values and biasing including quiescent voltage values minimizing component count. d) (10) What is the minimum value of the battery voltages that still meets the power requirement? e) (10) Given that class B amplifiers have distortion, explain how your circuit minimizes the problem. Class AB operation is not an option here. f) (10) What input signal is required to drive the amplifier to full