Operational amplifiers adder circuit

One example of such a circuit is the operational amplifier adder circuit, shown in Fig. 6.15. The signal at input A is summed with the signal at input B. This circuit has a variety of uses in communications circuitry. 

The outputs shown in Figs. 7.19, 7.20, 7.21, and 7.22 were summed by using the operational amplifier adder circuit shown in Fig. 7.18. The results of the breadboard are shown in Fig. 7.23, with the clock at the top and the staircase waveform at the bottom. The IsSpice, Micro-Cap, and PSpice results are shown in Figs. 7.24, 7.25, and 7.26, respectively. 

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