Datasheet

www.ti.com
PCM1774
SLAS551 – JULY 2007
Register 70
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 70 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 DEM1 DEM0 PFM1 PFM0 SPX1 SPX0 RSV OVER
IDX[6:0]: 100 0110b (46h): Register 70
DEM[1:0]: De-Emphasis Filter Selection
Default value: 00
A digital de-emphasis filter is in front of the interpolation filter. One of three de-emphasis filters can be selected
corresponding to the sampling rate, 32 kHz, 44.1 kHz, or 48 kHz.
DEM[1:0] De-Emphasis Filter Selection
00 OFF (default)
01 32 kHz
10 44.1 kHz
11 48 kHz
PFM[1:0]: Audio Interface Selection for DAC (Digital Input)
Default value: 00
The audio interface for the DAC digital input has I
2
S, right-justified, left-justified, and DSP formats.
PFM[1:0] Audio Interface Selection for DAC Digital Input
00 I
2
S format (default)
01 Right-justified format
10 Left-justified format
11 DSP format
SPX[1:0]: Digital Gain Control for DAC Input
Default value: 00
These bits are used to gain up the digital input data.
SPX[1:0] Digital Gain Control for DAC input
00 0 dB (default)
01 6 dB
10 12 dB
11 18 dB
OVER: Oversampling Control for Delta-Sigma DAC
Default value: 0
This bit is used to control the oversampling rate of delta-sigma DAC. When the PCM1774 operates at low
sampling rates (less than 24 kHz) and the SCKI frequency is less than 12.5 MHz, OVER = 1 is recommended.
OVER = 0 128 f
S
(default)
OVER = 1 192 f
S
, 256 f
S
, 384 f
S
26
Submit Documentation Feedback