Self-calibrating gain control system

摘要

A circuit for self-calibrating a gain control system samples the output of a digital amplifier coupled in series with one or more analog amplifiers to correct errors in a discrete stepped gain control. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit.

主权项

1. A step gain control system, comprising:
an analog unit operable to change an amplification of an input signal according to a first gain step; and a digital unit operable to correct for the first gain step by an incremental adjustment of one or more second gain steps, the digital unit being in series with the analog unit and a magnitude of a second gain step being smaller than a magnitude of the first gain step, wherein the digital unit comprises a level detector operable to measure a digital signal level, and wherein the digital unit comprises a filter for filtering the digital signal level over time.