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B.E. / B.Tech. (Part Time) DEGREE END SEMESTER EXAMINATIONS,APRIL / MAY 2014
ELECTRONICS AND COMMUNICATION ENGINEERING BRANCH
FOURTH SEMESTER
PTEC 283 / PTEC 244 / PTEC 9302 - LINEAR INTEGRATED CIRCUITS
Time: 3 hr
(REGULATIONS 2002 / 2005 / 2009)
Max Mark: 100
Answer ALL Questions
P a r t - A ( 1 0 X 2 = 20 Marks)
1. What is Active Load? why is it used in the internal OP-Amp circuits?
2. A 741C OP-AMP is used as an inverting amplifier with a gain of 50. The voltage gain Vs
frequency curve of 741C is flat upto 20KHz. What maximum peak to peak input signal can be
applied without distorting the output?
3. Draw the Log amplifier circuit.
4. For a schmitt trigger circuit, R =100Q, R ^ O K Q , V =0V, vi=1 V . sine wave and saturation
voltage=±14V. Determine threshold voltages VUT and V .
5. Draw the Block diagram of PLL IC 565.
6. What is the function of Compander ICs.. ,
7. A basic step of a 9-bit DAC is 10.3 mV. If 000000000 represents OV, what output is produced
if the input is 101101111?.
8. What is Resolution?
9. Draw the functional diagram of 723 regulator.
10. List the sources of noise in the OP A M P circuit.
2
ref
p
p
LT
P a r t - B ( 5 X 16 = 80 Marks)
11. ; ,.(i). Draw the Wilson current source and derive its output current.
(ii). Find V T for inverting amplifier with and without Rcomp. Assume R c o ^ g . S K Q ,
R1=10KQ ,V =10mV, l =300nA, l =50nA
(ii). Write short notes on frequency compensation in an Op-Amp.
(5)
0
os
B
os
12. (a), (i). With neat diagram explain the operation of an instrumentation amplifier using
3-OP-AMPs and derive its output voltage, state the important features of an
instrumentation amplifier.
(ii). Derive and design an Astable multivibrator for a time period of 2msec.
(or)
(3)
(8)
(8)
(8)
(b).(i). Derive the transfer function of Active narrow band pass filter and determine
its quality factor and bandwidth at resonance conditions.
(ii). Derive and design a wien bridge oscillator with the frequency of 1 KHz.
Assume relevant parameters
13. <a).(i). Explain the Four Quadrant Multiplier circuit with necessary diagrams.
(8)
(8)
(16)
(or)
(b). (i). Derive the Lock-in range of PLL.
(ii). Explain any two applications of PLL.
(8)
(8)
14. (a).(i). Explain the operation of voltage to frequency converter.
(ii). Briefly explain the operation of sample and Hold circuit and state its
applications.
^
(8)
(or)
(b).(i). Describe the functions of counter type AID converter.
(ii). Discuss the Successive Approximation AID converter and find the output of 4-bit
converter for an input of 3.217V with reference voltage of 5V.
(8)
15. (a).(i). Derive and Design an Astable multiplier using 555 Timer to get output waveform
at f=1 OKHz With a duty cycle of 40%.
(8)
(ii). Describe the operations of the Switched Capacitor filter with relevant diagrams.
(8)
(8)
(or)
(b). (i). With neat sketch, describe the operation of video amplifier.
(ii). Discuss the Opto couplers in detail.
(8)
(8)