CS4244 Datasheet, PDF (37/63 Pages) Cirrus Logic – 4 In/4 Out Audio CODEC with PCM and TDM Interfaces

4.6.3 DAC1-4 Path
CS4244
AIN1 (±)
AIN2 (±)
AIN3 (±)
AIN4 (±)
Multi-bit
 ADC
Digital Filters
VD
2.5 VDC
VA
5.0 VDC
2.5 V
LDO
Analog Supply
Channel Volume ,
Mute, Invert ,
Noise Gate
Master
Volume
Control
Interpolation
Filter
Multi-bit 
Modulators
DAC &
Analog
Filters
AOUT1 (±)
AOUT2 (±)
AOUT3 (±)
AOUT4 (±)
Serial Audio Interface
Level Translator
Control Port
VL
1.8 to 5.0 VDC
SDOUT1 SDOUT2
SDIN2 SDIN1
Frame Sync Master Clock In Serial Clock
Clock / LRCK
In/Out
Figure 26. DAC1-4 Path
INT RST
I²C Control
Data
The AOUT1-4 signals are driven by the data placed into the DAC1-4 path. This data can be placed into
the DAC1-4 path via the DAC1-4 Data Source settings in the control port. These settings allow the input
source to be selected from any of the up to 32 slots of data on the incoming TDM streams on SDIN1 and
SDIN2.
The DAC1-4 path also includes individual channel mutes. Separate volume controls are available for each
channel, along with a master volume control that simultaneously attenuates all four channels. The master
volume attenuation is added to any channel attenuation that is applied.
4.6.3.1 De-emphasis Filter
The CS4244 includes on-chip digital de-emphasis for 32, 44.1, and 48 kHz sample rates. It is not support-
ed for 96 kHz or for any settings in Double-speed Mode. The filter response is adjusted to be appropriate
for a particular base rate by the Base Rate Advisory bits. This filter response, shown in Figure 27, will vary
if these bits are not set appropriately for the given base rate. The frequency response of the de-emphasis
curve scales proportionally with changes in sample rate, F_S. Please see Section 6.9.2 DAC1-4 De-em-
phasis for de-emphasis control.
The de-emphasis feature is included to accommodate audio recordings that utilize 50/15 s pre-emphasis
equalization as a means of noise reduction.
DS900F2
37