On Semiconductor Analog Comparators
Analog comparators are devices used to compare two analog voltage signals and output either a digital high state or a digital low state depending on whether the compared signals are above or below a certain reference voltage. Dubbed the “World’s Simplest Microprocessor” by industry analysts, an analog comparator consists of an operational amplifier circuitry and a few resistors and capacitors. The operational amplifier provides power and the resistors and capacitors provide the necessary timing-related delay to the input signals. Generally, when the two input signals exceed the reference voltage, the output of the comparator is a logic high and when the input signals are below the reference, the output is a logic low. The thresholds for the inputs can be predetermined or can be adjustable depending on the application requirements. Analog comparators can also be made with programmable input thresholds or limits. These are useful in sensors or actuators that need to be adjusted to appropriate ranges.