R5221005 Linear Ic Applications

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Code No: R5221005

II B.Tech. II Semester (R05) Supplementary Examinations, April/May 2009 LINEAR IC APPLICATIONS (Electronics & Instrumentation Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain how large open circuit voltage gain of an op - amp can be obtained by using cascading of differential amplifier stages. (b) Explain ac analysis of differential amplifier.

[8+8]

2. (a) Discuss the Pole - Zero and Dominant pole compensation techniques for an op - amp. (b) An op - amp has a slew rate of 1.5V/µs. What is the maximum frequency of an output sinusoid of peak value 10 V at which the distortion sets in due to the slew rate limitation? [8+8] 3. (a) Derive the expressions for the output offset voltage of an op = amp in closed loop configuration (inverting). (b) List the linear and non - linear applications.

[10+6]

4. (a) Derive the output voltage of an antilog amplifier. (b) Write short notes on saw tooth waveform generator.

[8+8]

5. (a) List the conditions for oscillation in all the three types of oscillators, namely, RC phase shift, Wien - bridge and quadrature oscillators. (b) Design an op amp based relaxation oscillator and derive the frequency of oscillation.

[8+8]

6. (a) Configure a 555 timer as a Schmitt trigger and explain. (b) Explain frequency translation and FSK demodulation using 565 PLL.

[8+8]

7. (a) Compare R - 2R and weight resistor types of DACs. (b) Write short notes on A/D converters. (c) Define the following terms as related to DAC: i. Linearity ii. Resolution.

[8+4+4]

8. (a) What is balanced modulator and explain with neat diagram. (b) Explain the logic diagram and functional table of 4 to 1 line multiplexer. ?????

[8+8]

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Code No: R5221005

II B.Tech. II Semester (R05) Supplementary Examinations, April/May 2009 LINEAR IC APPLICATIONS (Electronics & Instrumentation Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Perform ac analysis of differential amplifier by using hybrid π model. (b) Why the differential amplifier responds to difference mode signals and rejects common mode signals. Explain the reason with suitable diagrams. [8+8] 2. (a) A 741 op - amp is used as an inverting amplifier with a gain of 25, the voltage gain, ‘Vs ’, frequency curve of 741 is flat up to 20kHz. What is the maximum peak-to-peak input signal that can be applied without distorting the output? (b) With a neat block diagram, explain the function of various building blocks of an op - amp. [6+10] 3. (a) Design a differentiator to differentiate an input signal that varies in frequency from 10 Hz to about 1KHz. If a sine wave of 1V peak at 1000 Hz is applied to this differentiator draw the output waveforms. (b) Why active differentiator circuits are not used in analog computer to solve differential equations. [10+6] 4. (a) Design a logarithmic amplifier for positive input voltages in the range 5mV to 50V. (b) With suitable circuit diagram explain the operation of a triangular wave generator using a comparator and a integrator. [8+8] 5. (a) An ideal LPF having fh = 5kHz is cascaded with HPF having fl = 4.8kHz. Sketch the frequency response of the cascaded filter. (b) Design a Ist order LPF for a high cut off frequency of 2kHz and pass band gain of 2.

[10+6]

6. (a) Explain the following in detail: i. Phase comparator ii. VCO (b) What is the role of LPF in PLL (c) Give any two applications of PLL and explain in detail.

[6+4+6]

7. Write shorts on: (a) Tracking type analog to digital converters. (b) Comparison of conversion times and hardware complexities of various analog to digital converters. [8+8] 8. (a) Draw the circuit diagram of sample and hold circuit and explain its working. (b) Draw the circuit diagram IC 1496 balanced modulator circuit and explain its operations. Sketch the output waveform for the square wave inputs with a phase difference ‘φ’. [8+8] ?????

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Code No: R5221005

II B.Tech. II Semester (R05) Supplementary Examinations, April/May 2009 LINEAR IC APPLICATIONS (Electronics & Instrumentation Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain how large open circuit voltage gain of an op - amp can be obtained by using cascading of differential amplifier stages. (b) Explain ac analysis of differential amplifier.

[8+8]

2. (a) Broadly classify the integrated circuits for a wide range of applications. (b) Explain the operation of op - amp using block diagram. (c) What is a practical op - amp? Draw its equivalent circuit?

[4+6+6]

3. (a) Draw the basic circuit diagram of an op - amp differentiator and explain its operation and stability. (b) Design a practical integrator to produce a peak voltage of 0.1V; when Vi = 10 sin(2π× 104t). Find the dc component at the output when the input is + 10 mV dc. [8+8] 4. Design and explain a saw tooth waveform generator using operational amplifier and plot the waveforms for the given specifications frequency = 5kHz, Vsat = ±12 Volts. [16] 5. (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.

[8+8]

6. List one application of the PLL and then briefly describe the role of the PLL in that application. [16] 7. (a) Sketch and explain the transfer characteristic of a DAC with necessary equations. (b) LSB of a 9 - bit DAC is represented by 19.6mv. 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]

8. (a) Classify the types of op - amp based multipliers. How a multiplier cab used to i. Double the incoming frequency. ii. Detect the phase angle of a signal. (b) Define the terms related to sample and hold circuit: i. Aperture time ii. delay time. Also, explain how these terms effect the operation of the circuit. ?????

[8+8]

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Code No: R5221005

II B.Tech. II Semester (R05) Supplementary Examinations, April/May 2009 LINEAR IC APPLICATIONS (Electronics & Instrumentation Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Explain in detail all the dc and ac characteristics of an ideal op - amp with relevant expressions. [16] 2. (a) What is the major difference between the power supply requirements of linear and digital Ics (b) Explain the Pole - Zero and Dominant pole compensation techniques for an op - amp.

[6+10]

3. (a) Calculate the exact closed loop gain inverting amplifier shown in figure1 if AOL = 2,00,000, Ri = 2MΩ and R0 = 75Ω. (b) Explain about any two linear and nonlinear applications of op - amp.

[8+8]

Figure 1: 4. (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.

[8+8]

5. (a) For the all pass filter, determine the phase shift φ between the input and output at f = 2kHz. To obtain a phase shift φ , what modifications are necessary in the circuit? (b) Derive the expression for the transfer function of 2nd order High pass filter. [8+8] 6. (a) Draw the circuit of a PLL AM detector and explain its operation. (b) What is the major difference between digital and analog PLLs?

[10+6]

7. (a) Sketch and explain the transfer characteristic of a DAC with necessary equations. (b) LSB of a 9 - bit DAC is represented by 19.6mv. 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]

8. (a) Explain how multiplier can be used to modulate and demodulate an AM signal. (b) What is meant by balanced modulator? Explain its function using neat diagram. ?????

[8+8]