Sunday, 27 April 2014

LINEAR AND DIGITAL (LICA) APPLICATONS Very Important Questions

LINEAR AND DIGITAL (LICA) APPLICATONS Very Important Questions
IC Applications

1. (a) Derive closed loop voltage gain, input resistance, output resistance and band-
width for inverting amplifier with feedback arrangement. [10+6]

(b) Explain any one of the frequency compensation technique in connection with
Op-amp.

2. (a) Explain how Op-amp used as a integrator and differentiator.

(b) With the help of a neat circuit diagram, explain the operation of instrumen-
tation amplifier of obtain the expression for its o/p voltage VO. [8+8]

3. (a) Define a Notch filter. Give its application.

(b) Determine the order of the Butterworth low-pass filter so that at ? = 1.5?3dB,
the magnitude response is down by at least 30 dB.

(c) Design a notch filter for fo =8 kHz and quality factor Q=10. Choose C=500pf
and assume necessary data. [5+6+5]

4. (a) Describe the operation of an analog phase detector.

(b) Analyze the behavior of an analog phase detector through necessary circuit
diagram, waveforms, mathematical expressions and characteristic curves.[8+8]

5. (a) Sketch and explain the transfer characteristic of a DAC with necessary equa-
tions.

(b) LSB of a 9-bit DAC is represented by 19.6 m Volts. If an input of 9 zero bits
is represented by 0 volts.
i. Find the output of the DAC for an input, 10110 1101 and 01101 1011.
ii. What is the Full scale Reading (FSR) of this DAC? [8+8]

6. (a) Draw the schematic circuits of CMOS NAND and CMOS NOR gates and
explain their functions with the help of Truth-Table.

(b) What are the advantages and disadvantages of CMOS over TTL gate?

(c) Which is the fastest saturated logic gate? and Why? [8+4+4]

7. (a) Write short notes on n- Bit parallel adder.

(b) Design a driver circuit for LCD display. [8+8]

8. (a) Explain with an example why asynchronous inputs are required in flip flops.

(b) Explain the operation of edge triggered T flip- flop. [8+8]

set 2

1. (a) What is cross over distortions and how it is eliminated in differential amplifier?

(b) Explain different methods of external frequency compensation in an Op-amp.

(c) Design an amplifier with a gain of +5 using one Op-amp ( make necessary
assumptions). [4+6+6]

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. [10+6]

3. (a) Derive the expression for frequency of oscillation of a RC phase shift oscillator
and explain the operation of the circuit.

(b) Design a second order low pass filter at a high cut off frequency of 1 KHz.
Derive the transfer function of the above filter. [8+8]

4. (a) Draw and explain the functional diagram of a 555 Timer.

(b) Explain the function of ‘reset’ pin. [14+2]

5. (a) Sketch and explain the transfer characteristic of a DAC with necessary equa-
tions.

(b) LSB of a 9-bit DAC is represented by 19.6 m Volts. If an input of 9 zero bits
is represented by 0 volts.
i. Find the output of the DAC for an input, 10110 1101 and 01101 1011.
ii. What is the Full scale Reading (FSR) of this DAC? [8+8]

7. (a) Design 1:8 Demultiplexer using two 1:4 Demultiplexer?

(b) Realize the following expression using 74×151 ICs and 74×139 IC [8+8]
F(Z) = ABCD + ABCD + ABCD + ABDE + ACDE + ABCE + ABCD

8. (a) Distinguish between Combinational circuits and sequential circuits.

(b) Write short notes on Clocked SR flip flop. [8+8]

SET 3

1. (a) List out the ideal characteristics of an Op-amp.

(b) With neat block diagram explain the function of various building blocks of an
Op-amp.

(c) Draw the equivalent circuit of an Op-amp. [3+10+3]

2. (a) Explain the operation of Zero crossing detector.

(b) Briefly mention the disadvantages of using Zero crossing detector and how it
is overcome in Schmitt Trigger?

(c) Draw a circuit using Op-amp which can work as adder (inverted and non-
inverted) and explain how it works. [4+4+8]

3. (a) Design a II order Butterworth Low-pass filter for a cut off frequency of 1KHz
and for a given normalized polynomial of S2+1.414S+1. Assume necessary
data.

(b) In the above circuit given (figure 3(b)ii) if the integrator components are
R1=120 K and C1 = 0.01µF,R3= 6.8 K R2= 1.2K, determine
i. Peak-to-peak triangular output amplitude.
ii. The frequency of triangular wave. [8+8]
Figure 3(b)ii

4. (a) Design a 555 Astable multivibrator to operate at 10 KHz with 40% duty cycle.

(b) Explain in which the 555 timer can be used as Astable multivibrator. [8+8]

5. (a) Draw the block diagram for a 2-bit parallel-comparator A/D converter and
explain the operation of the system.

(b) Draw a schematic diagram of a ladder network D/A converter. Explain the
operation of the converter. [8+8]

6. (a) Explain the operation of open drain output of CMOS?

(b) Explain the behavioral difference between simple transistor logic inverter and
Schottky logic inverter? [8+8]

7. (a) What is multiplexer? Draw the logic diagram of 4 to 1 line multiplexer?
(b) Design half adder using NAND gates only? [8+8]

8. (a) Explain with the help of neat diagram the simple structure of MOS ROM.
(b) Design MOD 5 synchronous counter. [8+8]

SET    4

1. (a) Give the pin diagram of IC741 and give its specifications.

(b) Discuss the differences between the differential amplifiers used in the first two
stages of Op-amp. [8+8]

2. (a) Explain the operation of Zero crossing detector.

(b) Briefly mention the disadvantages of using Zero crossing detector and how it
is overcome in Schmitt Trigger?

(c) Draw a circuit using Op-amp which can work as adder (inverted and non-
inverted) and explain how it works. [4+4+8]

3. (a) The cutoff frequency of a certain first order low pass filter is 2 KHz. Convert
this low pass filter to have a cutoff frequency of 3 KHz by using the frequency
scaling technique.

(b) How do we get a Notch filter from a band pass filter.

(c) What are the advantages of active filters over passive filters. [8+4+4]

4. (a) Give the block diagram of PLL and explain about each block in detail.

(b) Define the following terms with reference to PLL.
i. Lock range.
ii. Capture range.
iii. Pull-in-time. [10+6]

5. (a) Draw and compare the conversion times for tracking and successive approxi-

(b) A dual slope ADC uses a 12bit counter and a 8 MHz clock rate. The max
input voltage is +10V. The maximum integrator o/p voltage should be -8V,
when the counter has cycled through 2n counts. The capacitor used in the
integrator is 0.1µF. Find the value of the resistor of the integrator. [8+8]

6. (a) Explain the following terms with reference to TTL gate?
i. Logic levels.
ii. DC Noise margin.
iv. High-state fan out.

(b) List out TTL families and compare them with reference to propagation delay,
power consumption, speed-power product and low level input current? [8+8]

7. (a) Design the combinational circuit for common cathode 7 segment display/driver?

(b) Write short notes on gray code to Binary converter. [8+8]

8. (a) Write a note on applications, advantages and disadvantages of SRAM.

(b) Design MOD 6 synchronous counter. [8+8]