PCM1851 Datasheet, PDF (17/30 Pages) Burr-Brown (TI) – 24-BIT, 96-kHz STEREO A/D CONVERTER WITH 6 X 2-CHANNEL MUX AND PGA

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PCM1850
PCM1851
SLES108 − MARCH 2004
SERIAL AUDIO DATA INTERFACE
The PCM1850/1851 interfaces with the audio system through BCK (pin 2), LRCK (pin 1), and DOUT (pin 3).
Interface Mode
The PCM1850/1851 supports both master and slave modes as interface modes, and they are selected by mode control
via the serial port as shown in Table 4.
In master mode, the PCM1850/1851 provides the timing for serial audio data communications between the PCM1850/1851
and the digital audio processor or external circuit. While in slave mode, the PCM1850/1851 receives the timing for data
transfer from an external controller.
Table 4. Interface Mode
MD1
0
0
1
1
MD0
0
1
0
1
INTERFACE MODE
Slave mode (256 f_S, 384 f_S, 512 f_S, 768 f_S) (default)
Master mode (256 f_S)
Master mode (384 f_S)
Master mode (512 f_S)
Master Mode
In master mode, BCK and LRCK work as output pins, and these pins are controlled by timing which is generated in the
clock and timing control circuit of the PCM1850/1851. The frequency of BCK is fixed at 64 × LRCK. A 768-f_S system clock
is not available in master mode.
Slave Mode
In slave mode, BCK and LRCK work as input pins. The PCM1850/1851 accepts the 64 BCK/LRCK or 48 BCK/LRCK (only
for 384 f_S SCKI) format. A 768-f_S system clock is not available for f_S = 88.2 kHz and 96 kHz in slave mode.
Data Format
The PCM1850/1851 supports four audio data formats in both master and slave modes, and they are selected by mode
control via the serial port as shown in Table 5. Figure 23 illustrates the data formats in both slave and master modes.
FORMAT NO.
0
1
2
3
Table 5. Data Format
FMT2
1
1
0
0
FMT1
0
0
0
1
FMT0
1
0
0
1
FORMAT
Left-justified, 24-bit
I²S, 24-bit, (default)
Right-justified, 24-bit
Right-justified, 16-bit
17