WM9712L Datasheet, PDF (35/77 Pages) Wolfson Microelectronics plc – AC97 Audio and Touchpanel CODEC

Production Data
AUDIO MIXERS
WM9712L
MIXER OVERVIEW
The WM9712L has three separate low-power audio mixers to cover all audio functions required by
smartphones, PDAs and handheld computers. The diagram below shows the routing of the analogue
audio signals into the mixers. The numbers at the mixer inputs refer to the control register bits that
control the volume and muting for that particular signal.
MICL
MICR
LINE_IN
PCBEEP
PHONE_IN
DIFF /
STEREO/
MONO
(Reg 20h)
0Eh [12:8,4:0]
10h [12:8,4:0]
0Ch [4:0]
STEREO
DAC
18h [12:8,4:0]
PHONE MIX
HEADPHONE MIX
BACK SPKR MIX
M RECORD
U
X SELECT
1Ch / ALC
AUX
DAC
(12-BIT)
0/20
dB
1Ah [14]
STEREO
ADC
0Eh [7]
0/20
dB
0Eh [14,13]
18h [13]
1Ah [13:11]
10h [13]
12h [7:4]
0Ah [7:4]
0Ch [15]
10h [15]
14h [11:7]
18h [15]
14h [15:12]
0Ah [15:12]
12h [15:12]
10h [14]
18h [14]
12h [11:8]
0Ah [11:8]
0Ch [14]
PHONE
MIX
HEAD
PHONE/
EAR
SPEAKER
MIX
BACK
SPEAKER
MIX
OUT3VOL
(Reg 16h)
OUT3SRC
(Reg 16h)
VREF
MONOOUT
M
U
X
HPVOL
(Reg 04h)
INV
(Reg 02h)
-1
M
U
X
SRC
(Reg 16h)
OUT2VOL
(Reg 02h)
MONOOUT
(PHONE TX)
OUT3
ear
speaker
HPOUTL
HPOUTR
LOUT2
ROUT2
Stereo
headphone /
headset
loud
speaker
Figure 4 Audio Mixer Overview
HEADPHONE MIXER
The headphone mixer drives the HPOUTL and HPOUTR outputs. It also drives OUT3, if this pin is
connected to an ear speaker (phone receiver). The following signals can be mixed into the
headphone path:
• PHONE (controlled by register 0Ch, see “Audio Inputs”)
• LINE_IN (controlled by register 10h, see “Audio Inputs”)
• the output of the Record PGA (see “Audio ADC”, “Record Gain”)
• the stereo DAC signal (controlled by register 18h, see “Audio DACs”)
• the MIC signal (controlled by register 0Eh, see “Audio Inputs”)
• PC_BEEP (controlled by register 0Ah, see “Audio Inputs”)
• the AUXDAC signal (controlled by register 12h, see “Auxiliary DAC”)
In a typical smartphone application, the headphone signal is a mix of PHONE and sidetone (for
phone calls) and the stereo DAC signal (for music playback).
w
PD Rev 4.5 August 2006
35