SLAS510G March 2007 – February 2021 TLV320AIC3104
Ddetermines the level below which if the input speech average value falls, AGC considers it as a silence and hence brings down the gain to 0 dB in steps of 0.5 dB every sample period and sets the noise threshold flag. The gain stays at 0 dB unless the input speech signal average rises above the noise threshold setting. This ensures that noise does not get gained up in the absence of speech. Noise threshold level in the AGC algorithm is programmable from –30 dB to –90 dB relative to full scale. A disable noise gate feature is also available. This operation includes programmable debounce and hysteresis functionality to avoid the AGC gain from cycling between high gain and 0 dB when signals are near the noise threshold level. When the noise threshold flag is set, the status of gain applied by the AGC and the saturation flag should be ignored.