Patent ID: 8111103

Claim:
An amplifier circuit, comprising: an input amplifier having a first input end, a second input end, and a differential output pair; an output amplifier having a first input end, a second input end, and an output end, and the first and the second input ends of the output amplifier coupled to the differential output pair of the input amplifier; and a first diode device, a first end of the first diode device coupled to the output end of the output amplifier, and a second end of the first diode device coupled to the first input end of the output amplifier, wherein when a voltage difference between the output end of the output amplifier and the first input end of the output amplifier is greater than a barrier voltage of the first diode device, the first diode device is turned on, wherein the first diode device comprises at least one diode, an anode of the diode is coupled to the output end of the output amplifier, and a cathode of the diode is coupled to the first input end of the output amplifier.