A 1100ECT301122103 Pages: 2
Reg No.:_______________ Name:__________________________
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
Fifth Semester B.Tech Degree Regular and Supplementary Examination December 2022 (2019 Scheme)
Course Code: ECT 301
Course Name: LINEAR INTEGRATED CIRCUITS
Max. Marks: 100 Duration: 3 Hours
PART A
(Answer all questions; each question carries 3 marks) Marks
1 What are the ideal characteristics of an op-amp.? 3
2 Define Slew rate? Explain its significance. 3
3 Discuss the concept of virtual ground. 3
4 State how practical integrator is different from simple integrator circuit, with 3
relevant sketches.
5 Draw the circuit of an op-amp monostable multivibrator and write down the 3
expression of time period.
6 What are the advantages of active filters over passive filters? 3
7 Design a free-running multivibrator using 555 for a frequency of 1 KHz and a 3
duty cycle of 60%. Choose C= 0.1µF.
8 Mention three applications of PLL. 3
9 Explain the features and functional block diagram of IC 723. 3
10 List out DAC specifications. 3
PART B
(Answer one full question from each module, each question carries 14 marks)
Module -1
11 a) Derive CMRR, input resistance and output resistance of a dual input balanced 7
output differential amplifier configuration.
b) How a constant current bias circuit can be used to improve the CMRR of a 7
differential amplifier?
12 a) Draw the block diagram of an op-amp and explain the functions of each block. 7
b) Draw the equivalent circuit of an op-amp and explain the voltage transfer 7
characteristics of an op-amp.
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Module -2
13 a) Design the circuits to obtain the following output, Vo. (i) Vo = (5V1) 8
𝑉1 +𝑉2 +𝑉3
(ii) Vo= V1+ 2V2 (iii) 𝑉𝑜 = −( ) (iv) Vo = - 2V1- 5V2
3
b) Derive the following characteristics of voltage shunt amplifier: (i) Closed loop 6
voltage gain (ii)Input resistance (iii) Output resistance (iv)Bandwidth
14 a) What is a logarithmic amplifier? Draw the circuit and derive the transfer function 7
of a logarithmic amplifier.
b) Draw and explain the circuit of a voltage to current converter with grounded 7
load and derive its transfer function.
Module -3
15 a) With the help of circuit diagram explain the operation of RC phase shift 10
oscillator using op-amp. Derive the expression for frequency of oscillation and
the minimum gain requirement for sustained oscillation.
b) Design a first order low pass filter with the following specifications 4
(i)-3dB frequency 1 KHz , (ii) DC gain 20dB. Choose C= 0.01µF.
16 a) Design a circuit to generate a triangular waveform of 7VP-P at 1 KHz using an op- 7
amp having saturation voltage of ±14 V and draw the waveforms also.
b) Derive the equation for the frequency of oscillation of an opamp astable 7
multivibrator with the help of circuit diagram and waveforms.
Module -4
17 a) Draw the functional block diagram of 566 VCO and explain its operation. 7
b) Explain the operation of PLL. What is its lock range and capture range. 7
18 a) List the features of Timer IC 555 4
b) Draw the internal diagram of a 555 timer and explain its working as a 10
monostable multivibrator and derive the expression for its pulse-width.
Module -5
19 a) Discuss how the IC 723 can be used as high voltage regulator with current limit 7
and with current fold back.
b) Draw and explain the working of successive approximation type ADC. 7
20 a) With neat circuit diagram explain the working of a 3-bit flash ADC. 7
b) Explain the circuit of a 4-bit R-2R ladder DAC. 7
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