WM8980CGEFL/RV WOLFSON [Wolfson Microelectronics plc], WM8980CGEFL/RV Datasheet - Page 28

• Manufacturer Part Number: WM8980CGEFL/RV
• Description: Stereo CODEC with Speaker Driver and Video Buffer
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM8980
Figure 14 Input Boost Stage
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AUXILLIARY INPUTS
INPUT BOOST
Table 7 Input BOOST Stage Control
There are two auxiliary inputs, AUXL and AUXR which can be used for a variety of purposes such as
stereo line inputs or as a ‘beep’ input signal to be mixed with the outputs.
The AUXL/R inputs can be used as a line input to the input BOOST stage which has gain adjust of -
12dB to +6dB in 3dB steps (plus off). See the INPUT BOOST section for further details.
The AUXL/R inputs can also be mixed into the output channel mixers, with a gain of -15dB to +6dB
plus off.
In addition the AUXR input can be summed into the Right speaker output path (ROUT2) with a gain
adjust of -15 to +6dB. This allows a ‘beep’ input to be output on the speaker outputs only without
affecting the headphone or lineout signals.
Each of the stereo input PGA stages is followed by an input BOOST circuit. The input BOOST circuit
has 3 selectable inputs: the input microphone PGA output, the AUX amplifier output and the L2/R2
input pin (can be used as a line input, bypassing the input PGA). These three inputs can be mixed
together and have individual gain boost/adjust as shown in Figure 14.
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).
R47
Left Input
BOOST
control
R48
Right Input
BOOST
control
REGISTER
ADDRESS
8
8
BIT
PGABOOSTL
PGABOOSTR
LABEL
1
1
DEFAULT
Boost enable for left channel input
PGA:
0 = PGA output has +0dB gain through
input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
Boost enable for right channel input
PGA:
0 = PGA output has +0dB gain through
input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
DESCRIPTION
PP, Rev 3.8, May 2012
Pre-Production
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