WM8711BL_11 Datasheet, PDF (16/44 Pages) Wolfson Microelectronics plc – Ultra-Small Audio DAC with Headphone Amplifier

WM8711BL
Production Data
The software control for the line outputs is shown in Table 3.
REGISTER BIT
ADDRESS
LABEL
0000100
3
BYPASS
Analogue
Audio Path
Control
4
DACSEL
DEFAULT
1
0
Table 3 Output Software Control
The recommended external components are shown in Figure 9.
DESCRIPTION
Bypass Switch
1 = Enable Bypass
0 = Disable Bypass
DAC Select
1 = Select DAC
0 = Don’t select DAC
LINEOUT
R2
C1
R1
AGND
AGND
Figure 9 Line Outputs Application Drawing
Recommended values are C1 = 10F, R1 = 47k, R2 = 100
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.
HEADPHONE AMPLIFIER
The WM8711BL has a stereo headphone output available on LHPOUT and RHPOUT. The output is
designed specifically for driving 16 or 32 ohm headphones with maximum efficiency and low power
consumption. The headphone output includes a high quality volume level adjustment and mute
function.
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PD, Rev 4.2, December 2011
1644