WM8524

Production Data

w

PD, Rev 4.1, October 2011

14

Figure 8 I

DIGITAL AUDIO DATA SAMPLING RATES

The external master clock is applied directly to the MCLK input pin. In a system where there are a

number of possible sources for the reference clock, it is recommended that the clock source with the

lowest jitter be used for the master clock to optimise the performance of the WM8524.

The WM8524 has a detection circuit that automatically determines the relationship between the

master clock frequency (MCLK) and the sampling rate (LRCLK), to within ±32 system clock periods.

The MCLK must be synchronised with the LRCLK, although the device is tolerant of phase variations

or jitter on the MCLK.

If during sample rate change the ratio between MCLK and LRCLK varies more than once within 1026

LRCLK periods, then it is recommended that the device be taken into the standby state or the off

state before the sample rate change and held in standby until the sample rate change is complete.

This will ensure correct operation of the detection circuit on the return to the enabled state. For details

on the standby state, please refer to the Power up and down control section of the datasheet on page

16.

The DAC supports MCLK to LRCLK ratios of 128fs to 1152fs and sampling rates of 8kHz to 192kHz.

Table 3 shows typical master clock frequencies and sampling rates supported by the WM8524 DAC.

Sampling Rate

LRCLK

MASTER CLOCK FREQUENCY (MHz)

128fs

192fs

256fs

384fs

512fs

768fs

1152fs

8kHz

Unavailable

Unavailable

2.048

3.072

4.096

6.144

9.216

32kHz

Unavailable

Unavailable

8.192

12.288

16.384

24.576

36.864

44.1kHz

Unavailable

Unavailable

11.2896

16.9344

22.5792

33.8688

Unavailable

48kHz

Unavailable

Unavailable

12.288

18.432

24.576

36.864

Unavailable

88.2kHz

11.2896

16.9344

22.5792

33.8688

Unavailable

Unavailable

Unavailable

96kHz

12.288

18.432

24.576

36.864

Unavailable

Unavailable

Unavailable

176.4kHz

22.5792

33.8688

Unavailable

Unavailable

Unavailable

Unavailable

Unavailable

192kHz

24.576

36.864

Unavailable

Unavailable

Unavailable

Unavailable

Unavailable

Table 3 MCLK Frequencies and Audio Sample Rates