Production Data
WM8352
13.9.4 OUT3 AND OUT4
The additional analogue outputs OUT3 and OUT4 have independent mixers and can be used in a
number of different ways:
.
.
.
OUT3 and OUT4 as a stereo pair (OUT3 = left, OUT4 = right) to drive a headphone or line
load
OUT3 or OUT4 as pseudo-ground outputs for headphones connected directly (without DC
blocking capacitors) to OUT1L/OUT1R or OUT2L/OUT2R
OUT4 as a mono mix of left and right signals
The OUT3 and OUT4 output stages are powered from HPVDD and HPGND.
If OUT4 is providing a mono mix, it is recommended to reduce the level of OUT4 by 6dB to avoid
clipping in the event of 2 full-scale signals being combined. This is implemented via the OUT4_ATT
register field. When OUT4_ATT is asserted, then OUT4 = (L+R) / 2.
Figure 49 OUT 3 and OUT4 Mixers
PD, February 2011, Rev 4.4
89
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
