digital variable gain amplifier (DVGA)

A Digital Variable Gain Amplifier (DVGA) is a digitally controlled amplifier whose gain is adjusted with a digital signal. The gain setting is made in steps according to the smallest digital increments.

The gain control is usually done by switchable resistors in the feedback loop. Thus, with several switches and different resistors, various resistor combinations can be switched in the feedback branch and the gain can assume the desired gain factor. The switching functions can be performed by field effect transistors and controlled by a processor.