CS5345 datasheet(32/39 Pages) CIRRUS

32 / 39 page

CS5345

example settings.

6.8

ADC Input Control - Address 09h

6.8.1

PGA Soft Ramp or Zero Cross Enable (Bits 4:3)

Function:

Soft Ramp Enable

Soft Ramp allows level changes, both muting and attenuation, to be implemented by incrementally

ramping, in 1/8 dB steps, from the current level to the new level at a rate of 1 dB per 8 left/right clock

periods. See Table 10 on page 33.

Zero Cross Enable

Zero Cross Enable dictates that signal level changes, either by attenuation changes or muting, will

occur on a signal zero crossing to minimize audible artifacts. The requested level change will occur

after a time-out period between 512 and 1024 sample periods (10.7 ms to 21.3 ms at 48 kHz sample

rate) if the signal does not encounter a zero crossing. The zero cross function is independently mon-

itored and implemented for each channel. See Table 10 on page 33.

Soft Ramp and Zero Cross Enable

Soft Ramp and Zero Cross Enable dictate that signal level changes, either by attenuation changes or

muting, will occur in 1/8 dB steps and be implemented on a signal zero crossing. The 1/8 dB level

change will occur after a time-out period between 512 and 1024 sample periods (10.7 ms to 21.3 ms

at 48 kHz sample rate) if the signal does not encounter a zero crossing. The zero cross function is

independently monitored and implemented for each channel. See Table 10 on page 33.

Table 9. Example Gain and Attenuation Settings

Gain[5:0]

Setting

101000

-12 dB

000000

0 dB

011000

+12 dB

76543

210

Reserved

PGASoft

PGAZero

Sel2

Sel1

Sel0

CS5345 Datasheet(PDF) 32 Page - Cirrus Logic