An apparatus includes an amplifier and a gain control circuit. The amplifier may be configured to provide multiple gain steps. The gain control circuit may be configured to provide fast and precise changes between the multiple gain steps of the amplifier. The gain control circuit may be further configured to change an impedance of the amplifier to switch between the gain steps. The gain control circuit may be further configured to compensate for changes in frequency response related to changing the impedance. The gain control circuit may be further configured to inject a complementary charge to an input of the amplifier to correct a bias voltage deviation and a transient caused by the gain control circuit.