WM8986_07 WOLFSON [Wolfson Microelectronics plc], WM8986_07 Datasheet - Page 37

• Manufacturer Part Number: WM8986_07
• Description: Multimedia DAC With Class D Headphone and Line Out
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Pre-Production
3D STEREO ENHANCEMENT
ANALOGUE OUTPUTS
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The WM8986 has a digital 3D enhancement option to increase the perceived separation between the
left and right channels. The DEPTH3D setting controls the degree of stereo expansion.
Table 21 3D Stereo Enhancement Function
Note: When 3D enhancement is used, it may be necessary to attenuate the signal by 6dB to avoid
limiting.
The WM8986 has three sets of stereo analogue outputs. These are:
The outputs LOUT2 and ROUT2 are powered from AVDD2 and are capable of driving a 1V rms
signal (AVDD1/3.3).
LOUT1, ROUT1, OUT3 and OUT4 are powered from AVDD1
LOUT1, ROUT1, LOUT2 and ROUT2 have individual analogue volume PGAs with -57dB to +6dB
gain ranges.
There are four output mixers in the output signal path, the left and right channel mixers which control
the signals to headphone (and optionally the line outputs) and also dedicated OUT3 and OUT4
mixers.
LEFT AND RIGHT OUTPUT CHANNEL MIXERS
The left and right output channel mixers are shown in Figure 21. These mixers allow the analogue
inputs and the DAC left and right channels to be combined as desired. This allows a mono mix of the
DAC channels to be performed as well as mixing in external line-in from the AUX or speech from the
input PGAs.
The AUX and PGA path inputs have individual volume control from -15dB to +6dB and the DAC
volume can be adjusted in the digital domain if required. The output of these mixers is connected to
both the headphone (LOUT1 and ROUT1) and class D headphone (LOUT2 and ROUT2) and can
optionally be connected to the OUT3 and OUT4 mixers.
R41 (29h)
3D Control
REGISTER
ADDRESS
•
•
•
LOUT1 and ROUT1 which are normally used to drive a headphone load.
LOUT2 and ROUT2 – which can be used as class D or class AB headphone
drivers.
OUT3 and OUT4 – can be configured as a stereo line out (OUT3 is left output and
OUT4 is right output) or a differential output. OUT4 can also be used to provide a
mono mix of left and right channels.
3:0
BIT
DEPTH3D
LABEL
DEFAULT
0000
Stereo depth
0000 = Disabled
0001 = 6.67%
0010 = 13.3%
0011 = 20%
0100 = 26.7%
0101 = 33.3%
0110 = 40%
0111 = 46.6%
1000 = 53.3%
1001 = 60%
1010 = 66.7%
1011 = 73.3%
1100 = 80%
1101 = 86.7%
1110 = 93.3%
1111 = 100% (maximum 3D effect)
PP, Rev 3.1, February 2007
DESCRIPTION
WM8986
37