3.1 VOLTAGE COMPARATOR FUNDAMENTALS
A voltage comparator circuit compares the values of two voltages and produces an output to indicate the results. The output is always one of two values (i.e., the output is digital). Suppose, for example, we have two voltage comparator inputs labeled A and B. The circuit can be designed so that if input A is a more positive voltage than input B, the output will go to +VSAT. Similarly, if input A is less positive than input B, the output will go to −VSAT. In general, the voltage comparator circuit accepts two voltages as inputs and produces one of two distinct output voltages depending on the relative values of the two inputs.
During the preceding discussion, we were careful ...