WM8750L Datasheet, PDF (32/56 Pages) Wolfson Microelectronics plc – STEREO CODEC FOR PORTABLE AUDIO APPLICATIONS

WM8750L
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LOUT2/ROUT2 OUTPUTS
The LOUT2 and ROUT2 output pins are essentially similar to LOUT1 and ROUT1, but they are
independently controlled and can also drive an 8Ω mono speaker (see Speaker Output section). For
speaker drive, the ROUT2 signal must be inverted (ROUT2INV = 1), so that the left and right channel
are mixed to mono in the speaker [L–(-R) = L+R].
REGISTER
ADDRESS
R40 (28h)
LOUT2
Volume
BIT
LABEL
6:0 LOUT2VOL
[6:0]
7
LO2ZC
DEFAULT
1111001
(0dB)
0
R41 (29h)
ROUT2
Volume
8
LO2VU
0
6:0 ROUT2VOL 1111001
[6:0]
(0dB)
7
RO2ZC
0
8
RO2VU
0
R24 (18h)
4
ROUT2INV 0
Additional
Control (2)
Table 24 LOUT2/ROUT2 Volume Control
DESCRIPTION
Similar to LOUT1VOL
Left zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
Same as LO1VU
Similar ROUT1VOL
Left zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
Same as RO1VU
ROUT2 Invert
0 = No Inversion (0° phase shift)
1 = Signal inverted (180° phase shift)
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.
REGISTER
ADDRESS
R42 (2Ah)
MONOOUT
Volume
BIT
LABEL
6:0 MONOOUT
VOL [6:0]
7
MOZC
Table 25 MONOOUT Volume Control
DEFAULT
DESCRIPTION
1111001
(0dB)
0
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
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 (see Headphone Output section). 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.
REGISTER
ADDRESS
R24 (18h)
Additional
Control (2)
BIT
LABEL
8:7 OUT3SW
[1:0]
Table 26 OUT3 Select
DEFAULT
DESCRIPTION
00
OUT3 select
00 : VREF
01 : ROUT1 signal (volume controlled by
ROUT1VOL)
10 : MONOOUT
11 : right mixer output (no volume
control through ROUT1VOL)
PP Rev 1.77 May 2003
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