Integrated Circuits - Jun 2015

Electronics & Telecom Engineering (Semester 4)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Answer any one question from Q1 and Q2

1 (a) Draw the block diagram of op-amp and explain the function of each block in detail(6 marks) 1 (b) Compare different types of op-amp technologies.(3 marks) 1 (c) Explain the effect of temperature on:
(i) Input Bias Current
(ii) Input Offset Voltage
(iii) Input Resistance(3 marks) 2 (a) Find the Q-point V_C and I_B for dual input balanced output differential amplifier when, R_E=R_C=65 KΩ. Assume I_E=I_C, β=100 for both transistors Q₁ and Q₂; V_S=± 12 V.(6 marks) 2 (b) What is the need of frequency compensation? Explain any one method of frequency compensation.(6 marks)

Answer any one question from Q3 and Q4

3 (a) Design a lossy integrator with square wave input of 2 V_p-p and 5 Khz frequency. Draw input and output waveforms.(6 marks) 3 (b) Explain with a neat circuit diagram working of symmetric Schmitt trigger using op-amp. Also derive the equation for the trigger points.(6 marks) 4 (a) Design an adder using op-amp to get output expression as:
V₀= - (2V₁ + 3V₂+5V₃) Where V₁, V₂ and V₃ are inputs.(6 marks)

Answer any one question from Q5 and Q6

5 (a) With a neat circuit diagram, explain voltage to frequency Converter.(5 marks) 5 (b) Write a short note on Binary weighted Digital to Analog Converter (DAC).(5 marks) 5 (c) What output voltage would be produced by a D/A converter whose output range is 0 to 10 V and input binary number is:
(i) 10 (for a 2-bit DAC converter)
(ii) 0110 (for a 4-bit DAC)
(iii) 10111100 (for a 8-bit DAC).(3 marks) 6 (a) Write a short note on Flash type Analog to Digital Converter.(5 marks) 6 (b) What are the different types of V to I converter. Explain any one.(5 marks) 6 (c) List various specification of ADC.(3 marks)

Answer any one question from Q7 and Q8

7 (a) With the help of neat block diagram explain operation of PLL.(5 marks) 7 (b) What is the need of current boosting circuit ? Explain with the help of any one circuit.(5 marks) 7 (c) Draw block diagram of frequency multiplier. Draw input-output waveforms.(3 marks) 8 (a) For PLL circuit shown in Fig. 1, calculate the following:
(i) Free running frequency
(ii) Lock range
(iii) Capture range (6 marks) 8 (b) Write a short note on practical voltage regulator using LM317.(5 marks) 8 (c) Explain the following terms:
(i) Load Regulation
(ii) Line Regulation(2 marks)