sedra - cap2 - ece326ch02

Figure 2.1 Circuit symbol for the op amp.

2000 Prentice Hall Inc.

Figure 2.2 Equivalent circuit for the ideal op amp. AOL is very large (approaching infinity).


Figure 2.3 Op-amp symbol showing power supplies.


Figure 2.4 Inverting amplifier.


Figure 2.5 We make use of the summing-point constraint in the analysis of the inverting amplifier.


Figure 2.6 An inverting amplifier that achieves high gain with a smaller range of resistor values than required for the basic inverter.


Figure 2.7 Summing amplifier. See Exercise 2.1.


Figure 2.8 Circuits of Exercise 2.2.


Figure 2.9 Circuit of Exercise 2.3.


Figure 2.10a Schmitt trigger circuit and waveforms.


Figure 2.10b Schmitt trigger circuit and waveforms.


Figure 2.11 Noninverting amplifier.


Figure 2.12 Voltage follower.


Figure 2.13 Inverting or noninverting amplifier. See Exercise 2.4.


Figure 2.14 Differential amplifier. See Exercise 2.5.


Figure 2.15 Circuit for Exercise 2.6.


Figure 2.20 If low-value resistors are used, an impractically large current is required.


Figure 2.21 If very high value resistors are used, stray capacitance can couple unwanted signals into the circuit.


Figure 2.22 To attain large input resistance with moderate resistances for an inverting amplifier, we cascade a voltage follower with an inverter.


Figure 2.23 Amplifier designed in Example 2.4.


Figure 2.25 Bode plot of open-loop gain for a typical op amp.


Figure 2.27 Bode plots for Example 2.5.


Figure 2.28 For a real op amp, clipping occurs if the output voltage reaches certain limits.


Figure 2.29 Circuit of Example 2.8.


Figure 2.30 Output of the circuit of Figure 2.29 for RL = 10kV and Vs max = 5V.


Figure 2.31 Output of the circuit ofFigure 2.29 for RL = 10kV and vs(t) = 2.5 sin (105p t).


Figure 2.32 Circuit of Exercise 2.15.


Figure 2.33 Current sources and a voltage source model the dc imperfections of an op amp.


Figure 2.34a Circuit of Example 2.10.


Figure 2.34b Circuit of Example 2.10.


Figure 2.34c Circuit of Example 2.10.


Figure 2.34d Circuit of Example 2.10.


Figure 2.35 Adding the resistor R to the inverting amplifier circuit causes the effects of bias currents to cancel.


Figure 2.36 Noninverting amplifier, including resistor R to balance the effects of the bias currents. See Exercise~2.17.


Figure 2.40 Bode plot of the gain magnitude for the circuit of Figure 2.37.


Figure 2.42 Noninverting amplifier used to demonstrate nonlinear effects.


Figure 2.45 Output of the circuit of Figure 2.42 for RL = 10kV and Vim =5V.


Figure 2.46 Unity-gain amplifiers.


Figure 2.47 Inverting amplifier.


Figure 2.48 Ac-coupled inverting amplifier.


Figure 2.49 Summing amplifier.


Figure 2.50 Noninverting amplifier. This circuit approximates an ideal voltage amplifier.


Figure 2.51 Ac-coupled noninverting amplifier.


Figure 2.52 Ac-coupled voltage follower with bootstrapped bias resistors.


Figure 2.53 Differential amplifier.


Figure 2.54 Instrumentation-quality differential amplifier.


Figure 2.55 Voltage-to-current converter (transconductance amplifier).


Figure 2.56 Voltage-to-current converter with grounded load (Howland circuit).


Figure 2.57 Current-to-voltage converter (transresistance amplifier).


Figure 2.58 Current amplifier.


Figure 2.59 Variable-gain amplifier. See Exercise 2.21.


Figure 2.60 Integrator.


Figure 2.61 Square-wave input signal for Exercise 2.24.


Figure 2.62 Answer for Exercise 2.24a.


Figure 2.63 Differentiator.


Figure 2.64a Comparative Bode plots.


Figure 2.64b Comparative Bode plots.


Figure 2.64c Comparative Bode plots.


sedra - cap2 - ece326ch02

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