FAST RECOVERY SCHEME OF TRANSCONDUCTANCE GAIN FOR FOLDED CASCODE AMPLIFIER

摘要

A folded cascode amplifier (FCA) including cascode stages coupled in a stacked cascode configuration, an input stage, and a switch circuit. The stages may include first and second P-type stages and first and second N-type stages, in which the first N-type stage and the input stage receive first and second bias voltages, respectively. The switch circuit couples a first cascode bias voltage to the second P-type stage and couples a second cascode bias voltage to the first N-type stage in a high power state, and decouples the first and second cascode bias voltages in a low power state. A non-switched low current bias generator provides the first and second bias and cascode bias voltages, which remain substantially stable in the low and high power states. Only low parasitic capacitance nodes are switched between power states so that the gain of the FCA recovers very quickly for the high power state.