Datasheet

AIC36 Control Software

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Figure 12. Automatic Gain Control Panel

4.1.2.4 Dynamic Range Compression

Dynamic Range Compression (DRC) can be enabled by checking the Enable Left DRC and Enable

Right DRC boxes.

The level transfer characteristic graph is a function of the applied digital gain and the threshold parameter.

The graph line is separated into two piece-wise linear regions where the red line represents the level

range in which the DRC attenuation takes place, and the green line represents the level range in which

the signal is not affected by DRC. As an example, setting the threshold to -24 dB with a gain to 24 dB

implies that an input signal strength variation from -48 dB (threshold - gain) to 0 dB results in an output

signal strength variation from -24 dB to 0 dB, or a compression ratio of 2:1. Similarly, a threshold of -3 dB

with a gain of 24 dB implies that an input signal strength variation from -27 dB to 0 dB results in an output

signal strength variation from -3 dB to 0 dB, or a ratio of 9:1. Note that a gain less than 0 dB does not

result in expansion.

The Attack and Decay are time domain parameters that control the rate in which the applied gain reaches

the target gain after the threshold level is crossed. As an example, a fast attack rate quickly reaches the

target gain once the output signal crosses the programmed threshold region.

Other flags related to this feature can be accessed at the Status Flags panel.

TLV320AIC36EVM-K SLAU280A–March 2009–Revised October 2012

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