WM8731SEDSSLASHR datasheet(60/63 Pages) WOLFSON

Part #	WM8731SEDS/R

Description	Portable Internet Audio CODEC with Headphone Driver and Programmable Sample Rates

PDF	63 Pages

Scroll/Zoom	100%

Manufacturer	WOLFSON [Wolfson Microelectronics plc]

Direct Link	http://www.wolfsonmicro.com

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60 / 63 page

WM8731 / WM8731L

Production Data

PD Rev 4.2 November 2005

MINIMISING POP NOISE AT THE ANALOGUE OUTPUTS

To minimise any pop or click noise when the system is powered up or down, the following procedures

are recommended.

POWER UP SEQUENCE

•

Switch on power supplies. By default the WM8731 is in Standby Mode, the DAC is

digitally muted and the Audio Interface and Outputs are all OFF.

•

Set all required bits in the Power Down register (0Ch) to ‘0’; EXCEPT the OUTPD

bit, this should be set to ‘1’ (Default).

•

Set required values in all other registers except 12h (Active).

•

Set the ‘Active’ bit in register 12h.

•

The last write of the sequence should be setting OUTPD to ‘0’ (active) in register

0Ch, enabling the DAC signal path, free of any significant power-up noise.

POWER DOWN SEQUENCE

•

Set the OUTPD bit to ‘1’ (power down).

•

Remove the WM8731 supplies.

WM8731SEDS/R Datasheet(PDF) 60 Page - Wolfson Microelectronics plc