WM8766 datasheet(22/36 Pages) WOLFSON

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WM8766

Production Data

PD Rev 4.1 July 2005

DAC OUTPUT PHASE

The DAC phase control word determines whether the output of each DAC is non-inverted or inverted

BIT

LABEL

DEFAULT

DESCRIPTION

Bit

DAC

Phase

DAC1L/R

1 = invert

DAC2L/R

1 = invert

0000011

DAC Phase

8:6

PHASE

[2:0]

000

DAC3L/R

1 = invert

DIGITAL ZERO CROSS-DETECT

The digital volume control also incorporates a zero cross detect circuit which detects a transition

through the zero point before updating the digital volume control with the new volume. This is

enabled by control bit DZCEN.

BIT

LABEL

DEFAULT

DESCRIPTION

0001001

DAC Control

ZCD

DAC Digital Volume Zero Cross

Enable:

0: Zero cross detect enabled

1: Zero cross detect disabled

SOFTMUTE

The digital muting function used in Software and Hardware mode applies a softmute with the

operating characteristics shown in Figure 19.

Figure 19 Soft Mute Operation

When the softmute is applied the output of the device will decay towards VMID with a time constant of

approximately 64 input samples. When the mute is released, either manually or automatically by the

chip, the output will restart immediately from the current input sample.

ANALOGUE MUTE

Analogue mute can only be used in software mode and will cause the output of the selected DAC to

perform an analogue mute that clamps the output of the DAC to VMID. This function is dependent in

the IZD bit which is described in section INFINITE ZERO DETECT, later.

-2.5

-2

-1.5

-1

-0.5

0.5

1.5

0.001

0.002

0.003

0.004

0.005

0.006

Time(s)

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