WM8994 Datasheet, PDF (126/359 Pages) Wolfson Microelectronics plc – Multi-Channel Audio Hub CODEC for Smartphones

WM8994
Production Data
REGISTER BIT
ADDRESS
LABEL
DEFAULT
DESCRIPTION
R31 (001Fh) 5 HPOUT2_MUTE
1
HPOUT2 (Earpiece Driver) Mute
HPOUT2
Volume
0 = Un-mute
1 = Mute
4 HPOUT2_VOL
0
HPOUT2 (Earpiece Driver) Volume
0 = 0dB
1 = -6dB
R51 (0033h)
HPOUT2
Mixer
5 IN2LRP_TO_HPOUT2
0
Direct Voice (VRXN-VRXP) to
Earpiece Driver
0 = Mute
1 = Un-mute
4 MIXOUTLVOL_TO_HP
0
MIXOUTLVOL (Left Output Mixer
OUT2
PGA) to Earpiece Driver
0 = Mute
1 = Un-mute
3 MIXOUTRVOL_TO_HP
0
OUT2
MIXOUTRVOL (Right Output Mixer
PGA) to Earpiece Driver
0 = Mute
1 = Un-mute
Table 67 Earpiece Driver Mixer (HPOUT2MIX) Control
LINE OUTPUT MIXERS
The WM8994 provides two pairs of line outputs, both with highly configurable output mixers. The
outputs LINEOUT1N and LINEOUT1P can be configured as two single-ended outputs or as a
differential output. In the same manner, LINEOUT2N and LINEOUT2P can be configured either as
two single-ended outputs or as a differential output. The respective line output mixers can be
configured in single-ended mode or differential mode; each mode supports multiple signal path
configurations.
LINEOUT1 single-ended mode is selected by setting LINEOUT1_MODE = 1. In single-ended mode,
any of three possible signal paths may be enabled:
 MIXOUTL (left output mixer) to LINEOUT1P
 MIXOUTR (right output mixer) to LINEOUT1N
 MIXOUTL (left output mixer) to LINEOUT1N
LINEOUT1 differential mode is selected by setting LINEOUT1_MODE = 0. In differential mode, any of
three possible signal paths may be enabled:
 MIXOUTL (left output mixer) to LINEOUT1N and LINEOUT1P
 IN1L (input PGA) to LINEOUT1N and LINEOUT1P
 IN1R (input PGA) to LINEOUT1N and LINEOUT1P
The LINEOUT1 output mixers are controlled as described in Table 68. Care should be taken to avoid
clipping when enabling more than one path to the line output mixers. The LINEOUT1_VOL control
can be used to provide -6dB attenuation when more than one full scale signal is applied.
When using the LINEOUT1 mixers in single-ended mode, a buffered VMID must be enabled. This is
achieved by setting LINEOUT_VMID_BUF_ENA, as described in the “Analogue Outputs” section.
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PD, April 2012, Rev 4.4
126