Section 5.2 Operational Amplifiers
5.1 The equivalent model of a certain op amp is shown in Fig. 5.43. Determine:
(a) the input resistance
(b) the output resistance
(c) the voltage gain in dB
Figure 5.45
For Prob. 5.6.
5.7 The op amp in Fig. 5.46 has R_(i)=100kOmega , R_(o)=100Omega ,A=100,000. Find the differential voltage v_(d) and the output voltage v_(o).
Fi
Fi
5.2 The open-loop gain of an op amp is 100,000 . Calculate the output voltage when there are inputs of +10mu V on the inverting terminal and +20mu V on the noninverting terminal.
5.3 Determine the output voltage when -20mu V is applied to the inverting terminal of an op amp and +30mu V to its noninverting terminal. Assume that the op amp has an open-loop gain of 200,000 .
5.4 The output voltage of an op amp is -4V when the noninverting input is 1mV. If the open-loop gain of the op amp is 2 imes 10^(6), what is the inverting input?
5.5 For the op amp circuit of Fig. 5.44, the op amp has an open-loop gain of 100,000 , an input resistance of 10kOmega , and an output resistance of 100Omega . Find the voltage gain (v_(o))/(v_(i)) using the nonideal model of the op amp.
Figure 5.44
For Prob. 5.5.
5.6 Using the same parameters for the 741op amp in Example 5.1, find v_(o) in the op amp circuit of Fig. 5.45.
5.9 Determine v_(o) for each of the op amp circuits in Fig. 5.48.
Problems
203
Figure 5.46
For Prob. 5.7.
Section 5.3 Ideal Op Amp
5.8 Obtain v_(o) for each of the op amp circuits in Fig. 5.47,
Section 5. Operational Amplifiers
5.1 The cquivalent model of a certain op amp is shown in Fig. 5.43. Determine: (a the input resistance (b) the output resistance (c) the voltage gain in dB
m
Figure 5.45 For Prob. 5.6.
60
The op amp in Fig. 5.46 has R, = 100 k, R=100,A=100,000.Find the differential voltage 0 and the output voltage U,-
1.5M
810
Figure 5.43 For Prob. 5.1.
5.2 The open-loop gain of an op amp is 100,000. Calculate 10k 100k the output voltage when there are inputs of + 10 V W on the inverting terminal and +20 V on the noninverting terminal. 6.3 Determine the output voltage when 20 V is 10 applied to the inverting terminal of an op amp and +30 V to its noninverting terminal. Assume that Figure 5.46 the op amp has an open-loop gain of 200,000. For Prob. 5.7. 5.4 The output voltage of an op amp is 4 V when the noninverting input is I mV. If the open-loop gain of the op amp is 2 10, what is the inverting Section 5.3 Ideal Op Amp input? 5.8 Obtain for each of the op amp circuits in Fig. 5.47. 5.5 For the op amp circuit of Fig. 5.44, the op amp has an open-loop gain of 100,000, an input resistance of 10 k, and an output resistance of 100 . Find the voltage gain va/, using the nonideal model of the I0 kQ op amp. WMM 2k WW
Figure 5.44 For Prob. 5.5.
(b)
Figure 5.47 For Prob. 5.8.
5.6 Using the same parameters for the 741 op amp in Example 5.1, find , in the op amp circuit of Fig. 5.45.
5.9 Determine , for each of the op amp circuits in Fig, 5.48.
Problems
203
2 k WW
25 kQ WWW
5 kQ WM
*
10
o
Figure 5.51 For Prob. 5.12.
