(Common to PTEC 2254 — Linear Integrated Circuits for BE. (Part-Time) — Third Semester — ECE — Regulations 2009) 

Time : Three hours Maximum : 100 marks 

Answer ALL questions. 

PART A — (10 x 2 = 20 marks) 

1. State the limitations of discrete circuits.

2. Why do we use Aluminium for metallization? 

3. State reasons why integrator is called “lossy”. 

4. What is a precision rectifier? 

5. What do you mean by frequency synthesizing? 

6. A PLL frequency multiplier has an input frequency of ‘f’ and a decade counter is included in the loop. What will be the frequency of the PLL output? 

7. What output voltage would be produced by a D/A converter whose output range is 0 to 10 V and whose input binary number is 0110 for a 4 bit DAC. 

8. What is the main drawback of dual slope ABC? 

9. What are the limitations of three terminal regulator? 

10. What is a switched capacitor filter? 

PART B — (5 x 16 = 80 marks) 

11. (a) Explain the construction of a monolithic bipolar transistor. (16) 

Or 

(b) (i) Explain the working of a BJT differential amplifier with active load. (12) 

 (ii) Write down the characteristics and their respective values of an ideal operational amplifier. (4) 

12. (a) (i) What do you understand by an Instrumentation Amplifier? (2) 

 (ii) State the requirements of a good Instrumentation Amplifier. (4) 

 (iii) Draw the circuit diagram and explain the working of instrumentation Amplifier. (6) 

 (iv) Mention the specific advantages of three op-amp Instrumentation Amplifier circuit. (4) 

Or 

(b) (i) What do you understand by an Integrator? (2) 

 (ii) Draw and explain an deal active op-amp Integrator ckt (4) 

 (iii) Draw the I/O waveforms for: integrator (3 x ½ = 1½) 

 (1) Step input signal 

 (2) Square wave input signal 

 (3) Sine wave input signal 

 (iv) Derive the expression for change in output voltage. (3) 

 (v) List the applications of practical Integrator. (1½) 

 (vi) Design a practical integrator circuit with a dc gain of 10, to integrate a square wave of 10KHZ. (4) 

13. (a) (i) Explain the working of a Gilbert multiplier cell. (11) 

(ii) Explain the principle of operation of a PLL. (5) 

Or 

(b) (i) Explain the working of IC 565. (10) 

 (ii) Explain the application of PLL used for FM detection. (6) 

14. (a) Explain the working of 

 (i) R-2R ladder D/A converter (6) 

 (ii) Dual slope A/D converter. (10) 

Or 

(b) Explain the working of 

 (i) Weighted resistor D/A converter (6) 

 (ii) Successive approximation A/D converter. (10) 

15. (a) (i) Explain the working of monostable multivibrator. (14) 

 (ii) What are opto-couplers? (2) 

Or 

(b) (i) Explain the working of a general purpose voltage regulator. (14) 

 (ii) What is the need for isolation amplifiers? (2)