Basics of Electronics Engineering (12EC14) 30.10.2012
1. Determine the output vo in terms of v1, v2, v3 and v4, in the circuit of fig1. Assume the op amp to be ideal. Calculate vo, if v1 = 1V, v2 = 2V, v3 = 3V, and v4 = 4V, assuming all the resistors are equal.
2. In the voltage amplifier circuit of fig2, using an ideal op amp, determine the gain as a function of the potentiometer-setting, x. What is the range of the gain obtained? Show how to add a resistance, so that the gain range can be 1 to 21. What should be the resistor value?
3. In the voltage follower circuit of fig3, op amp used is ideal in all respects, except it has a finite gain, A. Determine vo/vin. If A is equal to 1000, calculate the error of the gain from that of the voltage follower with an ideal op amp.
4. Determine vo/vin in the circuit of fig4. Assume op amp is ideal.
5. Determine vo/vin in the circuit of fig5. The op amp used is ideal in all respects, except that it has a finite gain, A.
6. Determine vo/vin in the circuit of fig6. The op amp used is ideal in all respects, except that it has a finite gain, A.
7. Draw the summer circuits, using two ideal op amps, and calculate the different resistor values to obtain a) vo = 2v1-4v2+6v3 b) vo = v1+3v2+5v3-7v4-9v5-11v6, where v1,v2,v3,v4,v5 and v6 are the available inputs.
8. In the circuit of fig7, show that the differential gain is equal to R2/R1, if R1/R2 = R3/R4. Assume the op amp used is ideal.
9. Calculate the values of the different resistors in the circuit of fig7, so that Ad =100 with Acm = 0 and the input resistance is equal to 25KΩ.
10. In the circuit of fig8, determine IL in terms of vin, if R1 = R2.
11. The output signal of an op amp with a slew rate of 2.5V/µs, has a peak to peak value of 18V. Find the maximum frequency for undistorted output voltage.
12. An op amp has a differential gain of 2×104 and a CMRR of 86dB. Determine the output, if the differential input is 10µV and the common mode input is 10mV.
13. In the circuits of figs 9, 10 and11, determine the output voltage, vo. Assume the op amps to be ideal.
14. Draw the circuit of an Instrumentation amplifier, using three ideal amplifiers, and calculate the values of the different resistors to obtain a differential gain of 46dB with an infinite CMRR.
15. Design a Schmitt trigger circuit using an ideal op amp to obtain a hysteresis of 5V. The op amp is operating with +15V and -12V. For the designed circuit, determine the UTP and LTP.