WM8983GEFLSLASHV datasheet(27/124 Pages) WOLFSON

27 / 124 page

Production Data

WM8983

PD, Rev 4.3, May 2010

Notes:

The lineout charge time, tline_midrail_on, is determined by the VMID pin charge time. This time is

dependent upon the value of VMID decoupling capacitor and VMID pin input resistance and

AVDD power supply rise time. The values above were measured using a 4.7μF capacitor.

It is not advisable to allow DACDAT data input during initialisation of the DAC. If the DAC data

value is not zero at point of initialisation, then this is likely to cause a pop noise on the analogue

outputs. The same is also true if the DACDAT is removed at a non-zero value, and no mute

function has been applied to the signal beforehand.

The lineout discharge time, tline_midrail_off, is determined by the VMID pin discharge time. This time

is dependent upon the value of VMID decoupling capacitor and VMID pin input resistance. The

values above were measured using a 4.7μF capacitor.

The headphone charge time, thp_midrail_on, is dependent upon the value of VMID decoupling

capacitor and VMID pin input resistance and AVDD power supply rise time. The values above

were measured using a 4.7μF VMID decoupling capacitor.

The headphone discharge time, thp_midrail_off, is dependent upon the value of VMID decoupling

capacitor and VMID pin input resistance. The values above were measured using a 4.7μF VMID

decoupling capacitor.

The VMIDSEL and BIASEN bits must be set to enable analogue output midrail voltage and for

normal DAC operation.

RECOMMENDED L/ROUT1 ENABLE SEQUENCE

In order to minimise click noise, it is recommended that the WM8983 headphone outputs are enabled

using the following sequence:

•

Activate dual enable function DELEN = 1 (R42).

•

Enable L/ROUT1 amplifier core, LOUT1EN = 1, ROUT1EN = 1 (R2).

•

Enable output FETs, OUT1DEL = 1 (R42).

•

Disable DELEN = 0.

•

Reset OUT1DEL = 0.

Notes:

All outputs on WM8983 can also be enabled with a single write to enable bits in registers 2 and 3

without click minimisation. Disabling outputs does not require click minimisation.

WM8983GEFL/V Datasheet(PDF) 27 Page - Wolfson Microelectronics plc