WM8955L Datasheet, PDF (19/43 Pages) Wolfson Microelectronics plc – STEREO DAC FOR PORTABLE AUDIO APPLICATIONS

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WM8955L
LINE INPUTS AND OUTPUT MIXERS
The WM8955L provides the option to mix the DAC output signal with analogue line-in signals from
the LINEINL, LINEINR and MONOIN+ and MONOIN- pins. The level of the mixed-in signals can be
controlled with PGAs (Programmable Gain Amplifiers).
LINEINL, LINEINR, MONOIN+ and MONOIN- are high impedance, low capacitance AC coupled
analogue inputs. They are biased internally to the reference voltage VREF. Whenever these inputs
are muted or the device placed into standby mode, the inputs remain biased to VREF using special
anti-thump circuitry. This reduces any audible clicks that may otherwise be heard when re-activating
the inputs.
REGISTER
ADDRESS
R34 (22h)
Left Mixer (1)
BIT
LABEL
8
LD2LO
7
LI2LO
6:4 LI2LOVOL
R35 (23h)
8
Left Mixer (2)
7
RD2LO
MI2LO
6:4 MI2LOVOL
Table 6 Left Output Mixer Control
DEFAULT
DESCRIPTION
0
0
101
(-9dB)
0
0
101
(-9dB)
Left DAC to Left Mixer
0 = Disable (Mute)
1 = Enable Path
LINEINL Signal to Left Mixer
0 = Disable (Mute)
1 = Enable Path
LINEINL Signal to Left Mixer Volume
000 = +6dB
… (3dB steps)
111 = -15dB
Right DAC to Left Mixer
0 = Disable (Mute)
1 = Enable Path
MONOIN Signal to Left Mixer
0 = Disable (Mute)
1 = Enable Path
MONOIN Signal to Left Mixer Volume
000 = +6dB
… (3dB steps)
111 = -15dB
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Product Preview Rev 0.4 May 2003
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