Programmable gain amplifiers - or PGAs - are a type of electronic amplifier that allow you to control the gain in an electronic circuit (the ratio of output voltage, current or power to input) with digital signals. The gain can be set from less than 1 to over 100 volts.
Programmable gain amplifiers work by increasing the power of a signal (a time-varying voltage or current) in your electronic circuit.
They use electric power from a power supply to increase the amplitude of a signal. The amount of amplification provided by the programmable gain amplifier is measured by its gain.
Common applications for programmable gain amplifiers are motor control, signal and sensor conditioning, as well as in bar code readers and digital cameras. They can also be used for A/D converter driver applications, multiplexed analog applications, data acquisition, industrial instrumentation, test equipment and for use in medical instruments.