EE 40 Homework 5 Due October 18 2002 Nearly all problems taken from Electric Circuits by Nilsson and Riedel Notation The extra connections coming out of the amplifier indicate the rails Problem 1 For the time varying input voltage Vs and ideal operational amplifier circuit below sketch VO as a function of time 0 5 120 k 0 25 Vs 5V 0 7 5 k 0 25 Vs 5 V 6 8 k 0 5 0 1 2 3 4 time s Problem 2 Va Vb Given two input voltages Va and Vb which cannot be detached from ground design an ideal operational amplifier circuit which has the average of Va and Vb as its output voltage Assume that the amplifier will always be operating in its linear region i e ignore the rail voltages Problem 3 Assume that the ideal operational amplifier on the next page is operating in its linear region i e ignore the rail voltages a Calculate the power delivered to the 16 k resistor b Repeat part a with the amplifier removed from the circuit that is with the 16 k resistor connected in series with the voltage source and the 64 k resistor c Find the ratio of the power found in part a to that found in part b Problem 3 continued 64 k 16 k 320 mV Problem 4 Consider the operational amplifier circuit below with the variable max 50 k resistor in the feedback path Will the amplifier operate in its linear region for all between 0 and 1 If not for what range of does the amplifier operate linearly i e not hit the rails 50 k 5V 1 6 k 250 mV 6 4 k 5 V 6 8 k Problem 5 The inverting amplifier in the circuit at left has an input resistance Ri of 500 k an output resistance Ro of 5 k and an open loop gain A of 250 000 Assume that the amplifier is operating in its linear region i e ignore the rails 180 k Vcc 2 k Vo Vin Vcc a Calculate the voltage gain Vo Vin b Repeat part a using the ideal op amp model
View Full Document
Unlocking...