Circuits and methods for signal gain control

A signal gain control circuit, comprising:

• a gain stage receiving and amplifying an analog signal by a first gain factor adjusted by a gain adjusting signal in a substantially periodic manner with a first period, and outputting an amplified signal;
• an analog to digital converter coupled to the gain stage, converting the amplified signal to a first digital signal comprising a stream of samples;
• an amplifying device coupled to the analog to digital converter, adjusting a second gain factor in a substantially periodic manner with a second period in accordance with at least one characteristic metric of the distribution of the first digital signal and multiplying the first digital signal by the second gain factor to generate a second digital signal;
• and
• a first gain adjusting device coupled to the gain stage, detecting a signal strength of the second digital signal and generating the gain adjusting signal accordingly in a substantially periodic manner with the first period.