Production Data

WM8501

w

PD, Rev 4.2, July 2009

17

POWER UP/DOWN SEQUENCE

POWER UP/DOWN SEQUENCE

For click free operation, the WM8501 should be powered up and down in a specific sequence.

Power-up:

1.

Power up AVDD and DVDD and wait to settle

2.

Turn on clocks and data (MCLK, BCLK, LRCLK, SDATA)

3.

Switch ENABLE pin from low to high

Power-down:

1.

Switch Enable from high to low

2.

Remove clocks and data

3.

Power down AVDD and DVDD

RECOMMENDED ANALOGUE LOW PASS FILTER

Ω

Ω

Ω

Ω

Note: Capacitors should be COG dielectric.

An external single pole RC filter is recommended (see Figure 18) if the device is driving a

wideband amplifier. However the WM8501 does contain an internal low pass filter which should

be adequate in most applications.