WM8721 datasheet(13/37 Pages) WOLFSON

No. de pieza	WM8721

Descripción Electrónicos	Internet Audio DAC with Integrated Headphone Driver

PDF	37 Pages

Scroll/Zoom	100%

Fabricante Electrónico	WOLFSON [Wolfson Microelectronics plc]

Página de inicio	http://www.wolfsonmicro.com

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13 / 37 page

Production Data

WM8721 / WM8721L

PD Rev 4.0 November 2004

VMID

LINEOUT

FROM DAC

TO HEADPHONE AMP

DACSEL

Figure 8 Line Output Schematic

The line output is muted by either programming the DACMU (digital) bit as per table 2, or by writing

to the DACSEL (analogue) bit as per table 3. Whenever the DAC is muted or the device placed into

standby mode the DC voltage is maintained at the line outputs to prevent any audible clicks from

being present.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0000100

Analogue

Audio Path

Control

DACSEL

DAC Select

1 = Select DAC

0 = Don’t select DAC

Table 3 Output Software Control

The recommended external components are shown in Figure 9.

AGND

LINEOUT

Figure 9 Line Outputs Application Drawing

Recommended values are C1 = 10

µF, R1 = 47k, R2 = 100Ω

C1 forms a DC blocking capacitor to the line outputs. R1 prevents the output voltage from drifting so

protecting equipment connected to the line output. R2 forms a de-coupling resistor preventing

abnormal loads from disturbing the device. Note that poor choice of dielectric material for C1 can

have dramatic effects on the measured signal distortion at the output.

WM8721 Datasheet(PDF) 13 Page - Wolfson Microelectronics plc