Patent ID: 7643805

Claim:
A variable gain amplifier circuit with automatic gain control comprising: an amplifier unit having a predetermined gain, the amplifier circuit being capable of receiving an input signal and generating an output signal, the output signal having a first peak; and an automatic gain control loop with a plurality of peak detectors connected to the amplifier unit, the automatic gain loop being capable of receiving the output signal and a reference signal with a second peak, the automatic gain loop with the plurality of peak detectors further being capable of detecting the first peak and the second peak, comparing the first peak with the second peak and generating a control signal, the control signal being used by the amplifier unit to regulate the predetermined gain, wherein the plurality of peak detectors further comprising; a first peak detector connected to the amplifier unit, the first peak detector being capable of detecting the first peak and providing a first peak signal indicative of the first peak; a second peak detector being capable of detecting the second peak and providing a second peak signal indicative of the second peak; and a comparator circuit connected to the first and second peak detectors and the amplifier unit, the comparator circuit being capable of comparing the first and second peak signals generating the control signal and providing the control signal to the amplifier unit.