# JNTU previous papers B Tech 1st Sem Examinations,Linear and digital IC application, November 2008

JNTU previous papers

JNTU, B.Tech,I-Semester

LINEAR AND DIGITAL IC APPLICATION, November 2008

( Computer Science & Engineering, Information Technology and Computer Science & Systems Engineering)

SET-1

1. (a) Why is emitter resistor RE replaced by a constant current bias circuit in differential amplifier stage of an OP-AMP? 

(b) Explain why open loop configurations are not used in linear applications 

(c) For an OP-AMP, PSRR=70dB(min),CMRR=105,differential mode gainAd=105.

The output voltage changes by 20V in 4 microseconds. Calculate i)numerical

value of PSRR ii) Common mode gain iii) Slew rate of the OP-AMP. 

2. (a) What is a clipper? With circuit diagram, explain the operation of positive

and negative clippers 

(b) Describe the principle of operation of a precision half wave rectifier with wave forms 

3. (a) What feedback is preferred for oscillators and why? What is the effect of negative feedback? 

(b) Design an OP-AMP based relaxation oscillator and derive the frequency of

oscillation. 

4. (a) Explain the operation of Monostable multivibrator using 555 timer. Derive

the expression of time delay of a Monostable multivibrator using 555 timer.



(b) Design a Monostable multivibrator using 555 timer to produce a pulse width

of 100 m sec. 

5. Discuss the significance of phase detector, Low pass filter, amplifier and a VCO in

PLL. 

6. (a) Explain the operation of a delay equalizer circuit with neat sketches. Derive

an expression relating input and output voltages of the equalizer. [8+2]

(b) For the all pass filter, determine the phase shift between input and output at

f=2 kHz. To obtain a positive phase shift. What modifications are necessary

in the circuit? 

7. (a) What is meant by AOI Logic. Explain with the help of example. 

(b) Draw the circuit of an improved version of D.T.L. 3-input Nand gate, and explain its operations with the help of Truth Table If hFE of each transistor is 40, find FAN-OUT of the circuit. 

8. (a) List out different types of A/D converters and compare their merits and de-

merits. 

(b) Give the schematic circuit of an A/D converter widely used in digital volt-

meters and explain its operation. Derive expression for output voltage.