Production Data
WM8955BL
POWER MANAGEMENT
The WM8955BL has two control registers that allow users to select which functions are active. For
minimum power consumption, unused functions should be disabled. To avoid any pop or click noise,
it is important to enable or disable functions in the correct order (see Applications Information)
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
00
DESCRIPTION
R25 (19h)
8:7
VMIDSEL
VMID resistor divider select
Power
00 – VMID disabled
Manageme
nt (1)
01 – 50kΩ divider enabled
10 – 500kΩ divider enabled
11 – 5kΩ divider enabled (for fast start-up)
6
8
VREF
DACL
0
0
VREF (necessary for all other functions)
R26 (1Ah)
DAC Left Enable
Power
0=off
Manageme
nt (2)
1=on
7
6
5
4
3
2
DACR
0
0
0
0
0
0
DAC Right Enable
0=off
1=on
LOUT1
ROUT1
LOUT2
ROUT2
MOUT
LOUT1 Output Buffer* Enable
0=off
1=on
ROUT1 Output Buffer* Enable
0=off
1=on
LOUT2 Output Buffer* Enable
0=off
1=on
ROUT2 Output Buffer* Enable
0=off
1=on
MONOOUT Output Buffer and Mono Mixer
Enable
0=off
1=on
1
OUT3
0
OUT3 Output Buffer Enable
0=off
1=on
Note:
* The left mixer is enabled when LOUT1=1 or LOUT2=1. The right mixer is enabled when
ROUT1=1 or ROUT2=1.
Table 26 Power Management
PD Rev 4.1 February 2007
35
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
