ACS422A68TAGZBX8 IDT, ACS422A68TAGZBX8 Datasheet - Page 22

• 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.
range control processing element implements limiting, dynamic range compression, and dynamic range expansion
functions.
3.6.
The Limiter function will limit the output of the DSP module to the Class-D and DAC modules. If the signal is greater
than 0dB it will saturate at 0dB as the final processing step within the DSP module.
There are times when the user may intentionally want the output Limiter to perform this saturation, for example +6dB of
gain applied within the DSP gain control and then limited to 0dB when output to the Class-D module would result in a
clipped signal driving the speaker output. This clipped signal would obviously contribute to increased distortion on the
speaker output which from the user listening perception it would “sound louder”.
At other times, the system implementor may wish to protect speakers from overheating or provide hearing protection by
intentionally limiting the output level before full scale is reached. A limit threshold, independent of the compressor
threshold is provided for this purpose. It is expected that the limit threshold is set to a higher level than the compressor
threshold.
3.7.
The traditional compressor algorithm provides two functions simultaneously (depending on signal level). For higher
Limiter
Compressor
-10
-12
-14
-16
-18
-20
-22
-2
-4
-6
-8
0
Compressed Output Range
Natural Output Range
Output Range
-22
Expanded
Compressor Threshold:
Expander Threshold:
-20
Compressor Ratio:
Expander Ratio:
Limit Threshold:
-18
Figure 8. Gain Compressor, Output vs Input
-16
-14.25 dBFS
3:1
1:2
-14
-18 dBFS
-6 dBFS
-12
Input (dBFS)
Compressor Threshold
22
Expander Threshold
-10
-8
Limit Threshold
-6
-4
-2
0
ACS422X68
V1.6 01/13