Patent ID: 7242251

Claim:
A controllable amplifier circuit configured to adjust a gain thereof in discrete values, comprising: a signal input configured to receive an input signal; a signal output configured to output an amplified signal based on a gain of the amplifier circuit; a control input configured to receive a control signal indicative of a desired gain of the amplifier circuit; a control circuit configured to vary the gain of the amplifier circuit based on a state of the control signal; a first amplifier stage and at least one second amplifier stage each arranged between the signal input and the signal output, and each comprising a first gain and a switching input for selective activation thereof coupled to the control circuit; and at least one third amplifier stage arranged between the signal input and the signal output, and comprising a second gain and a switching input for selective activation thereof coupled to the control circuit, wherein the control circuit comprises a first control block configured to provide single-ended signal processing, and a second control block configured to provide push-pull signal processing, and further configured to supply control signals from the first control block to the first and at least one second amplifier stage for a gain change in the first and at least one second amplifier stage, and configured to supply control signals from the second control block to the first and at least one second and at least one third amplifier stage for a gain change in the at least one third amplifier stage.