CS42L56 View Datasheet(PDF) - Cirrus Logic

Part Name

Description

MFG CO.

CS42L56

Ultralow Power, Stereo Codec with Class H Headphone Amp

Cirrus Logic 

CS42L56

whenever a threshold violation occurs. It then modifies the signal level by adjusting the gain settings in

the PGA and ADC digital volume control accordingly.

As shown in Figure 18, if the input signal level rises above the maximum threshold, the ALC first lowers

the PGA gain settings. It then decreases the ADC digital volume at a programmable “attack” rate and

maintains the resulting level below the maximum threshold. In contrast, if the input signal level falls below

the minimum threshold, the ALC first increases the ADC digital volume settings and then increases the

PGA gain settings at a programmable “release” rate. However, once an attack or release operation has

been performed on an input signal, the ALC does not change the PGA or the digital volume control set-

tings until the next threshold violation occurs.

Input (before ALC)

ALCMIN[2:0]

below full scale

ALCMAX[2:0]

below full scale

PGA

Response

ADC Vol.

Cntrl.

Response

Total ALC

Response

Output

(after ALC)

ALCMIN[2:0]

below full scale

ALCMAX[2:0]

below full scale

ARATE[5:0]

RRATE[5:0]

Figure 18. ALC Operation

ARATE[5:0]

DS851F2

35

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