CS4525 datasheet(37/91 Pages) CIRRUS

37 / 91 page

DS726A1

CS4525

6.1.4.10

Peak Signal Limiter

When enabled, the limiter monitors the digital output following the volume control block, detects when

peak levels exceed a selectable maximum threshold level and lowers the volume at a programmable at-

tack rate until the signal peaks fall below the maximum threshold. When the signal level falls below a se-

lectable minimum threshold, the volume returns to its original level (as determined by the individual and

master volume control registers) at a programmable release rate. Attack and release rates are affected

by the soft ramp/zero cross settings and sample rate, Fs.

Recommended settings: Best limiting performance may be realized with the fastest attack and slowest

release setting with soft ramp enabled in the control registers. Use the “minimum” bits to set a threshold

slightly below the maximum threshold to cushion the sound as the limiter attacks and releases.

By default, the limiter affects all channels when the maximum threshold is exceeded on any single chan-

nel. This default functionality is designed to keep all output channels at the same volume level while the

limiter is in use. This behavior can be disabled by clearing the LimitAll bit in the Limiter Cfg 1 register.

Max[2:0]

Output

(after Limiter)

Input

RRate[5:0]

ARate[5:0]

Volume

Limiter

Min[2:0]

Attack/Release Sound

Cushion

Attack/Release Sound

Cushion

Figure 17. Peak Signal Detection & Limiting

CS4525 Datasheet(PDF) 37 Page - Cirrus Logic