Pre-Production
WM8985
The input PGA paths can have a +20dB boost (PGABOOSTL/R=1), a 0dB pass through
(PGABOOSTL/R=0) or be completely isolated from the input boost circuit (INPPGAMUTEL/R=1).
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R47 (2Fh)
8
PGABOOSTL
1
Boost enable for left channel input
PGA:
Left Input
BOOST
control
0 = PGA output has +0dB gain
through input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
R48 (30h)
8
PGABOOSTR
1
Boost enable for right channel input
PGA:
Right Input
BOOST
control
0 = PGA output has +0dB gain
through input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
Table 8 Input BOOST Stage Control
The Auxiliary amplifier path to the BOOST stages is controlled by the AUXL2BOOSTVOL[2:0] and
AUXR2BOOSTVOL[2:0] register bits. When AUXL2BOOSTVOL/AUXR2BOOSTVOL=000 this path
is completely disconnected from the BOOST stage. Settings 001 through to 111 control the gain in
3dB steps from -12dB to +6dB.
The L2/R2 path to the BOOST stage is controlled by the LIP2BOOSTVOL[2:0] and the
RIP2BOOSTVOL[2:0] register bits. When L2_2BOOSTVOL[6:4] and R2_2BOOSTVOL[6:4]=000
the L2/R2 input pin is completely disconnected from the BOOST stage. Settings 001 through to 111
control the gain in 3dB steps from -12dB to +6dB.
PP, Rev 3.4, October 2006
35
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
