Patent ID: 6476745
Filing Date: 2002-11-05
Classification: H03M,H04B

Abstract:
An Automatic Gain Control System, comprising:a variable gain microphone amplifier; an analog-to-digital converter coupled to said microphone amplifier; a variable gain anti aliasing filter coupled to said analog to digital converter; and a processing element, coupled to said filter, programmed to detect saturation of digital output from the anti aliasing filter, and further programmed to adjust the gain of the microphone amplifier and of the anti aliasing filter to eliminate said saturated output, gain correction information is transmitted from the processing element to the variable gain microphone amplifier and the anti aliasing filter by employing the unused 3 bits of the 16-bit PCM (Pulse Code Modulation) data word used to communicate between the processing element and the filter, thus eliminating any additional connections.