ACS422A68TAGZBX8 IDT, ACS422A68TAGZBX8 Datasheet - Page 23

• Manufacturer Part Number: ACS422A68TAGZBX8
• Description: Interface - CODECs
• Manufacturer: IDT

Specifications of ACS422A68TAGZBX8

• Rohs: yes
• Part # Aliases: IDTACS422A68TAGZBX8

ACS422x68
LOW-POWER, HIGH-FIDELITY, INTEGRATED CODEC
©2011 INTEGRATED DEVICE TECHNOLOGY, INC.
level signals, it can provide a compression function to reduce the signal level. For lower level signals, it can provide an
expansion function for either increasing dynamic range or noise gating.
The compressor monitors the signal level and, if the signal is higher than a threshold, will reduce the gain by a pro-
grammed ratio to restrict the dynamic range. Limiting is an extreme example of the compressor where, as the input sig-
nal level is increased, the gain is decreased to maintain a specific output level.
In addition to limiting the bandwidth of the compressed audio, it is common for compressed audio to also compress the
dynamic range of the audio. The expansion function in the ACS422x68 can help restore the original dynamics to the
audio.
The expander is a close relative of the compressor. Rather than using signal dependent gain to restrict the dynamic
range, the expander uses signal dependent gain to expand the dynamic range. Thus if a signal level is below a particu-
lar threshold, the expander will reduce the gain even further to extend the dynamic range of the material.
3.7.1.
Configuration
This compressor limiter provides the following configurable parameters.
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Compressor
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Limiter
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Expander
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Two level detection algorithms
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Threshold – The threshold above which the compressor will reduce the dynamic range of
the audio in the compression region.
Ratio – The ratio between the input dynamic range and the output dynamic range. For
example, a ratio of 3 will reduce an input dynamic range of 9db to 3db.
Attack Time – The amount of time that changes in gain are smoothed over during the attack
phase of the compressor.
Release Time – The amount of time that changes in gain are smoothed over during the
release phase of the compressor.
Makeup gain – Used to increase the overall level of the compressed audio.
Threshold – The threshold above which the limiter will reduce the dynamic range of the
audio in the compression region.
Target – The limit of the output level (typically set to the same as threshold).
Attack Time – The amount of time that changes in gain are smoothed over during the attack
phase of the limiter.
Release Time – The amount of time that changes in gain are smoothed over during the
release phase of the limiter.
Threshold – The threshold below which the expander will increase the dynamic range of the
audio.
Ratio – The ratio between the input dynamic range and the output dynamic range of the
audio in the expansion range. For example a ratio of 3 will take an input dynamic range of
9db and expand it to 27db.
Attack Time – The amount of time that changes in gain are smoothed over during the attack
phase of the expander
Release Time - The amount of time that changes in gain are smoothed over during the
release phase of the expander.
RMS – Use an RMS measurement for the level.
Peak – Use a peak measurement for the level.
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ACS422X68
V1.6 01/13