Assign
2
EE 101: Assignment # 6 Note: Assume OP AMPS are ideal unless mentioned otherwise, and saturate at ± 10 V. 1. For a standard non-inverting amplifier with resistances R 2 and R 1 , find the gain if the (non-ideal) OP AMP open loop gain is A vo (instead of ∞). Confirm that your equation reduces to the usual equation in the limiting case. 2. Design a non-inverting amplifier of gain +200 and an input resistance of 2 KΩ. Find the output voltage of the circuit if, in addition, the OP AMP’s offset voltage is 5 mV. 3. Design an OP AMP circuit with very high input impedance and gain − 1000. 4. Design a simple low-pass filter with a cut-off frequency of 10 kHz and a low frequency gain of magnitude 10. 5. Draw a circuit to perform the function v o = + 10(v 1 v 2 )/v 3 2 . 6. Make a multiplier circuit v o = (v 1 v 2 )/10. Note that this is a standard multiplier equation, because if the inputs v 1 and v 2 have a peak value of ± 10 V, then the output voltage is also ± 10 V. Show how this multiplier can be easily converted into a squarer circuit. Design an OP AMP circuit with the squarer circuit as the feedback element, and show that this can be used as a square root circuit. 7. Find the gain, input resistance and output resistance of a buffer circuit if the OP AMP in non-ideal (open loop gain A vo , input resistance is R id , output resistance R o ). 8. Show that the circuit shown in Fig. 1 acts like a “precision” diode, that is a diode with almost zero cut-in voltage. Explain how it can be used to “detect” a very small amplitude AM radio wave. 9. For the circuit shown in Fig. 2, find v o in terms of v 1 and v 2 . 10. For the circuit shown in Fig. 3, find the frequency of oscillation, and the amplitude of the waveform across the capacitor. 11. For the circuit shown in Fig. 4, find the frequency of oscillation. Plot the waveform at points A and B. Repeat if the points C and D are not at ground but at variable voltages V C and V D . What does varying these voltages accomplish? 12. Modify the circuit of Fig. 4 to make a voltage controlled oscillator (VCO), in which the frequency of a square/triangle wave varies linearly with an input voltage v i . (Hint: Use a multiplier circuit somehow inserted between the two OP AMPS of Fig.4.)
-
Upload
viplov-jain -
Category
Documents
-
view
4 -
download
0
description
EE
Transcript of Assign
EE 101: Assignment # 6
Note: Assume OP AMPS are ideal unless mentioned otherwise, and saturate at ± 10 V. 1. For a standard non-inverting amplifier with resistances R2 and R1, find the gain if the
(non-ideal) OP AMP open loop gain is Avo (instead of ∞). Confirm that your equation reduces to the usual equation in the limiting case.
2. Design a non-inverting amplifier of gain +200 and an input resistance of 2 KΩ. Find the output voltage of the circuit if, in addition, the OP AMP’s offset voltage is 5 mV.
3. Design an OP AMP circuit with very high input impedance and gain − 1000.
4. Design a simple low-pass filter with a cut-off frequency of 10 kHz and a low frequency gain of magnitude 10.
5. Draw a circuit to perform the function vo = + 10(v1v2)/v3
2.
6. Make a multiplier circuit vo = (v1v2)/10. Note that this is a standard multiplier equation, because if the inputs v1 and v2 have a peak value of ± 10 V, then the output voltage is also ± 10 V. Show how this multiplier can be easily converted into a squarer circuit. Design an OP AMP circuit with the squarer circuit as the feedback element, and show that this can be used as a square root circuit.
7. Find the gain, input resistance and output resistance of a buffer circuit if the OP AMP in non-ideal (open loop gain Avo, input resistance is Rid, output resistance Ro).
8. Show that the circuit shown in Fig. 1 acts like a “precision” diode, that is a diode with almost zero cut-in voltage. Explain how it can be used to “detect” a very small amplitude AM radio wave.
9. For the circuit shown in Fig. 2, find vo in terms of v1 and v2. 10. For the circuit shown in Fig. 3, find the frequency of oscillation, and the amplitude of the
waveform across the capacitor. 11. For the circuit shown in Fig. 4, find the frequency of oscillation. Plot the waveform at
points A and B. Repeat if the points C and D are not at ground but at variable voltages VC and VD. What does varying these voltages accomplish?
12. Modify the circuit of Fig. 4 to make a voltage controlled oscillator (VCO), in which the
frequency of a square/triangle wave varies linearly with an input voltage vi. (Hint: Use a multiplier circuit somehow inserted between the two OP AMPS of Fig.4.)
