 MORE IN Linear Integrated Circuits
VTU Electronics and Communication Engineering (Semester 4)
Linear Integrated Circuits
June 2013
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1 (a) With a neat circuit diagram, explain the basic op-amp circuit.
6 M
1 (b) Give definitions of the following op-amp parameter and give their typical values for 741 op-amp: i) CMRR; ii) Input offset voltage; iii) PSRR
6 M
1 (c) Draw a neat circuit diagram for a direct coupled non-inverting op-amp circuit and explain the design steps.
4 M
1 (d) Two signals each ranging from 0.1V to 1V are to be summed. Using 741 op-amp design a suitable inverting summing circuit.
4 M

2 (a) Draw a neat circuit diagram and give design steps for a i) capacitor coupled voltage followers; ii) Capacitor coupled inverting amplifier.
8 M
2 (b) What is meant by setting upper cutoff in a capacitor op-amp? Explain how it is done in an inverting op-amp.
6 M
2 (c) A capacitor coupled non-inverting op-amp is to have AF=100 and Vo=5V with RL=10K? and f1=100 Hz. Design suitable circuit.
6 M

3 (a) Define gain margin and phase margin and explain how they help for stability check.
6 M
3 (b) What is meant by frequency response compensation? Why it is required? Explain the working of a phase lag compensation network.
8 M
3 (c) Define: i) slew rate effect; ii) UGB Determine the maximum distortion free free output amplitude for a voltage follower when 741 op-amp is used with f2=800 kHz and S=0.5 V/μS.
6 M

4 (a) What are the advantages of precision rectifier over ordinary rectifier? Explain the working of a precision half wave rectifier.
6 M
4 (b) Draw the circuit of an instrumentation amplifier using op-amp, explain the working and derive the expression for output.
10 M
4 (c) Draw the circuit and explain the working of an op-amp limiter to have voltage levels VZ+VD for negative cycle of input and -Vsat for positive cycle of input.
4 M

5 (a) Write a brief note on following op-amp applications:
i) Negative clamper using op-amp
ii) Log amplifiers using op-amp.
12 M
5 (b) Explain the working of Wein bridge oscillator using op-amp.
8 M

6 (a) Explain how op-amp can be used as inverting and non-inverting comparator. What are the limitations? Explain how the limitations can be overcome using a Schmitt trigger.
10 M
6 (b) An inverting Schmitt trigger circuit is to have UTP=0V, LTP=-1V. Design a suitable circuit using bipolar op-amp with ±15V supply.
5 M
6 (c) Design a second order active low pass filter for a cutoff frequency of 7kHz.
5 M

7 (a) Mention the advantages of IC voltage regulators. Draw the internal schematic for IC723 regulator and briefly explain the working.
10 M
7 (b) Explain briefly about 78XX and 79XX series voltage regulators.
10 M

8 (a) Draw the internal schematic of 555 IC, configuring it for astable operation, explain the working.
8 M
8 (b) Explain the working of D to A converter using R-2R network.
6 M
8 (c) Explain the working of A to D converter using successive approximation method.
6 M

More question papers from Linear Integrated Circuits