Arithmetic Function Circuits
This chapter presents several circuits designed to perform mathematical operations, including adding, subtracting, averaging, absolute value, and sign changing. Several other common but more complex circuits that perform mathematical functions are presented in Chapter 11.
An adder circuit has two or more signal inputs, either AC or DC, and a single output. The magnitude and polarity of the output at any given time is the algebraic sum of the various inputs. In Chapter 2, we discussed an inverting adder circuit, called an inverting summing amplifier. If we make the feedback resistor and all input resistors the same size, the circuit provides a mathematically correct sum (i.e., no voltage gain). ...