Patent ID: 8416019

Claim:
A digitally controlled gain control system for digitally controlling the gain of an amplifier receiving an analog input signal, the system comprising: an amplifier configured to amplify an analog input signal in accordance with a gain level represented by a digital gain control signal applied to the system; and a clock controller configured to generate a clocking signal so that the gain level is set in a plurality of increments of gain change in response to the clocking signal; a zero crossing detector configured to detect when the input signal from the amplifier is within a selected range of zero amplitude; and a gain interpolator configured to provide a gain control signal to the amplifier, wherein the gain interpolator includes a binary up/down counter that is configured to count between an initial gain value and a new gain value; wherein each of the plurality of increments of gain change is provided while the input signal is within the selected range of zero amplitude; wherein the clock controller is configured to pass zero crossing pulses from the zero crossing detector to the gain interpolator, wherein the zero crossing pulses indicate when the input signal from the amplifier is within a selected range of zero amplitude.