wm9712l Wolfson Microelectronics plc, wm9712l Datasheet - Page 29

• Manufacturer Part Number: wm9712l
• Description: Ac?97 Audio And Touchpanel Codec
• Manufacturer: Wolfson Microelectronics plc

Production Data
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ANALOGUE AUDIO OUTPUTS
HEADPHONE OUTPUTS – HPOUTL AND HPOUTR
The following sections give an overview of the analogue audio output pins. For more information on
recommended external components, please refer to the “Applications Information” section.
The HPOUTL and HPOUTR (pins 39 and 41) are designed to drive a 16Ω or 32Ω headphone or a
line output. They can also be used as line-out pins. The output signal is produced by the headphone
mixer.
The signal volume on HPOUTL and HPOUTR can be independently adjusted under software control
by writing to register 04h. When HPOUTL and HPOUTR are not used, the output drivers can be
disabled to save power (see “Power Management” section). Both pins remain at the same DC level
(the reference voltage VREF) when they are disabled, so that no click noise is produced.
Table 15 HPOUTL / HPOUTR Control
04h
HPOUTL /
HPOUTR
Volume
REGISTER
ADDRESS
15
13:8
7
5:0
BIT
MUTE
HPOUTLVOL
ZC
HPOUTRVOL
LABEL
1
000000
(0dB)
0
00000
(0dB)
DEFAULT
Mute HPOUTL and HPOUTR
1: Mute (OFF)
0: No Mute (ON)
HPOUTL Volume
000000: 0dB (maximum)
000001: -1.5dB
… (1.5dB steps)
011111: -46.5dB
1xxxxx: -46.5dB
Zero Cross Enable
0: Change gain immediately
1: Change gain only on zero crossings,
or after time-out
HPOUTR Volume
Similar to HPOUTLVOL
DESCRIPTION
PD Rev 4.5 August 2006
WM9712L
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