WM8581 datasheet(35/94 Pages) WOLFSON

35 / 94 page

Product Preview

WM8581

PP Rev 1.0 March 2006

Figure 23 Application and Release of Mute

Figure 23 shows the application and release of MUTE whilst a full amplitude sinusoid is being played

at 48kHz sampling rate. When MUTE (lower trace) is asserted, the output (upper trace) begins to

decay exponentially from the DC level of the last input sample. The output will decay towards VMID

with a time constant of approximately 64 input samples. If MUTE is applied to all channels for 1024

or more input samples the DAC will be muted if IZD is set. When MUTE is de-asserted, the output

will restart immediately from the current input sample.

All other means of muting the DAC channels will cause a much more abrupt muting of the output.

DE-EMPHASIS MODE

A digital de-emphasis filter may be applied to each DAC channel. The de-emphasis filter for each

stereo channel is enabled under the control of DEEMP[3:0]. DEEMP[0] enables the de-emphasis

filter for DAC 1, DEEMP[1] enables the de-emphasis filter for DAC 2, DEEMP[2] enables the de-

emphasis filter for DAC 3 and DEEMP[3] enables the de-emphasis filter for DAC 4.

BIT

LABEL

DEFAULT

DESCRIPTION

3:0

DEEMP[3:0]

0000

De-emphasis mode select:

DEEMP[0] = 1, enable De-

emphasis on DAC1.

DEEMP[1] = 1, enable De-

emphasis on DAC2.

DEEMP[2] = 1, enable De-

emphasis on DAC3.

DEEMP[3] = 1, enable De-

emphasis on DAC4.

R17

DAC CONTROL 3

11h

DEEMPALL

0 = De-emphasis controlled by

DEEMP[3:0]

1 = De-emphasis enabled on all

DACs

Table 26 De-emphasis Register

Refer to Figure 40, Figure 40, Figure 41, Figure 42, Figure 43, Figure 44 and Figure 45 for details of

the De-Emphasis modes at different sample rates.

-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)

WM8581 датащи(PDF) 35 Page - Wolfson Microelectronics plc

WM8581 датащи(HTML) 35 Page - Wolfson Microelectronics plc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94

датащи скачать

ссылки URL