Programmable variable gain amplifier and rf receiver including the same

Abstract

A programmable variable gain amplifier includes at least three amplifiers. A first amplifier is configured to amplify an input signal. A second amplifier, which includes a programmable output load stage, is configured to receive an output signal from the first amplifier and to output a first differential output signal. The output load stage includes multiple first switches and multiple first diode-connected transistors that are open-circuited or short-circuited by the first switches. A third amplifier, which includes a programmable current mirror input stage, is 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 includes multiple second switches and multiple second transistors that are open-circuited or short-circuited by the plurality of second switches. The second transistors respectively form current mirrors with the first diode-connected transistors corresponding to the second transistors.