WM8955BL Wolfson Microelectronics, WM8955BL Datasheet - Page 25

• Manufacturer Part Number: WM8955BL
• Description: Stereo DAC
• Manufacturer: Wolfson Microelectronics

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Production Data
LOUT2/ROUT2 OUTPUTS
The LOUT2 and ROUT2 output pins are essentially similar to LOUT1 and ROUT1, but they are
independently controlled and can drive an 32Ω BTL earpiece. For BTL drive, the ROUT2 signal must
be inverted (ROUT2INV = 1), so that the left and right channel are mixed to mono in the earpiece [L-(-
R) = L+R].
Table 15 LOUT2/ROUT2 Control
MONO OUTPUT
The MONOOUT pin can drive a mono line output. The signal volume on MONOOUT can be adjusted
under software control by writing to MONOOUTVOL.
Table 16 MONOOUT Volume Control
OUT3 OUTPUT
The OUT3 pin can drive a 16Ω or 32Ω headphone or a line output or be used as a DC reference for a
headphone output. It can be selected to either drive out an inverted ROUT1 or inverted MONOOUT
for e.g. an earpiece drive between OUT3 and LOUT1 or differential output between OUT3 and
MONOOUT.
OUT3SW selects the mode of operation required.
Table 17 OUT3 Select
R40 (28h)
LOUT2
Volume
R41 (29h)
ROUT2
Volume
R23 (17h)
R24 (18h)
Additional (2)
R42 (2Ah)
MONOOUT
Volume
R23 (17h)
R24 (18h)
Additional (2)
REGISTER
REGISTER
REGISTER
ADDRESS
ADDRESS
ADDRESS
0
0
6:0
7
8
6:0
7
8
4
6:0
7
8:7
BIT
BIT
BIT
LOUT2VOL
LO2ZC
LO2VU
ROUT2VOL
RO2ZC
RO2VU
TOEN
ROUT2INV
MONOOUT
VOL
MOZC
TOEN
OUT3SW
LABEL
LABEL
LABEL
1111001
(0dB)
0
0
1111001
(0dB)
0
0
1
0
1111001
(0dB)
0
1
00
DEFAULT
DEFAULT
DEFAULT
similar to LOUT1VOL
Left zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
similar to LO1VU
similar to ROUT1VOL
Right zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
similar to RO1VU
as for LOUT1 / ROUT1
ROUT2 Invert
0 = No Inversion (0° phase shift)
1 = Signal inverted (180° phase shift)
MONOOUT Volume
1111111 = +6dB
… (80 steps)
0110000 = -67dB
0101111 to 0000000 = Analogue MUTE
MONOOUT zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
as for LOUT1 / ROUT1
OUT3 select
00 : VREF
01 : ROUT1
10 : MONOOUT
11 : right mixer output
DESCRIPTION
DESCRIPTION
DESCRIPTION
PD Rev 4.1 February 2007
WM8955BL
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