WM8956 View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'WM8956' PDF : 80 Pages View PDF
WM8956
Production Data
REGISTER
ADDRESS
R2 (02h)
LOUT1
Volume
BIT
LABEL
8
OUT1VU
7
LO1ZC
6:0 LOUT1VOL
[6:0]
R3 (03h)
ROUT1
Volume
8
OUT1VU
7
RO1ZC
6:0 ROUT1VOL
[6:0]
Table 18 LOUT1/ROUT1 Volume Control
DEFAULT
DESCRIPTION
0
0
0000000
(MUTE)
0
0
0000000
(MUTE)
Headphone Volume Update
0 = Store LOUT1VOL in intermediate
latch (no gain change)
1 = Update left and right channel gains
(left = LOUT1VOL, right = intermediate
latch)
Left zero cross enable
0 = Change gain immediately
1 = Change gain on zero cross only
LOUT1 Volume
1111111 = +6dB
… 1dB steps down to
0110000 = -73dB
0101111 to 0000000 = Analogue
MUTE
Headphone Volume Update
0 = Store ROUT1VOL in intermediate
latch (no gain change)
1 = Update left and right channel gains
(left = intermediate latch, right =
ROUT1VOL)
Right zero cross enable
0 = Change gain immediately
1 = Change gain on zero cross only
ROUT1 Volume
Similar to LOUT1VOL
See "Volume Updates" for more information on volume update bits, zero cross and timeout operation.
CLASS D SPEAKER OUTPUTS
The SPK_LP/SPK_LN and SPK_RP/SPK_RN output pins are class D speaker drivers. Each pair is
independently controlled and can drive an 8 BTL speaker (see Speaker Output section). Output
mixer volume is relative to AVDD, while an additional boost stage is available to accommodate higher
SPKVDD1/SPKVDD2 supply voltages. This allows AVDD to be run at a lower voltage to save power,
while maximum output power can be delivered to the load, utilising the full range of
SPKVDD1/SPKVDD2. Note that the BTL speaker connection provides an additional +6dB gain at the
output.
Figure 14 Speaker Boost Operation
w
PD, November 2011, Rev 4.1
32
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