WM8761

Production Data

w

PD, Rev 4.6, October 2011

14

Figure 8 DSP ‘Late’ Mode Timing

Figure 9 DSP ‘Early’ Mode Timing

AUDIO DATA SAMPLING RATES

The master clock for WM8761 supports audio sampling rates from 128fs to 768fs, where fs is the

audio sampling frequency (LRCIN) typically 32kHz, 44.1kHz, 48kHz, 96kHz or 192kHz. The

master clock is used to operate the digital filters and the noise shaping circuits.

The WM8761 has a master clock detection circuit that automatically determines the relation

between the master clock frequency and the sampling rate (to within +/- 8 master clocks). If there

is a greater than 8 clocks error, the interface shuts down the DAC and mutes the output. The

master clock should be synchronised with LRCIN, although the WM8761 is tolerant of phase

differences or jitter on this clock.

SAMPLING

RATE

(LRCIN)

MASTER CLOCK FREQUENCY (MHz) (MCLK)

128FS

256fs

512fs

768fs

32kHz

4.096

8.192

16.384

24.576

44.1kHz

5.6448

11.2896

22.5792

33.8688

48kHz

6.144

12.288

24.576

36.864

96kHz

12.288

24.576

Unavailable

Unavailable

192kHz

24.576

Unavailable

Unavailable

Unavailable

Table 1 Master Clock Frequencies Versus Sampling Rate

For sample rate support of MCLK at 192fs and 384fs, please refer to the pin-compatible WM8761B

device.

LRCIN

BCKIN

DIN

Input Word Length (16 bits)

1/f

LEFT CHANNEL

1

2

1

1

LSB

MSB

16

2

1

1

RIGHT CHANNEL

NO VALID DATA

1

Max 4 BCKIN's

LRCIN

BCKIN

DIN

Input Word Length (16 bits)

1/f

LEFT CHANNEL

1

2

1

1

LSB

MSB

1

2

1

1

RIGHT CHANNEL

NO VALID DATA

1

1

max 4 BCKIN's