Patent ID: 7860468

Claim:
A programmable variable gain amplifier, comprising: a first amplifier configured to amplify an input signal; a second amplifier comprising a programmable output load stage, the second amplifier being configured to receive an output signal from the first amplifier and to output a first differential output signal, the output load stage comprising a plurality of first switches and a plurality of first diode-connected transistors that are open-circuited or short-circuited by the plurality of first switches; and a third amplifier comprising a programmable current mirror input stage, the third amplification unit being configured to receive the first differential output signal from the second amplifier through the current mirror input stage and to output a second differential output signal, the current mirror input stage comprising a plurality of second switches and a plurality of second transistors that are open-circuited or short-circuited by the plurality of second switches, wherein the plurality of second transistors respectively form current mirrors with the plurality of first diode-connected transistors corresponding to the second transistors.