Patent ID: 7388427
Filing Date: 2008-06-17
Classification: H03F

Abstract:
1. An integrated circuit comprising: a first circuit branch, coupled between a first node and a second node, comprising N amplifier stages in series, wherein N is an integer 0 or greater, a second circuit branch, coupled between the second node and a third node, comprising M amplifier stages in series, wherein M is an integer 1 or greater; a voltage control circuit coupled to the least one amplifier stage of the M amplifier stages of the second branch, wherein the voltage control circuit, in response to a mode control voltage, provides a control signal to the least one amplifier stage of the M amplifier stages of the second branch to place the at least one amplifier stage of the M amplifier stages of the second branch in an on state or an off state; and a third circuit branch, coupled between the second node and the third node, comprising an impedance transformer unit, wherein during a first mode of operation of the circuit, at least one amplifier stage of the M amplifier stages of the second branch is in an off state, consuming less power than in an on state, and a signal output from the N amplifier stages of the first branch passes substantially through the third circuit branch, and during a second mode of operation of the circuit, the M amplifier stages of the second circuit branch are in the on state and a signal output from N amplifier stages of the first branch passes substantially through the second circuit branch.