Pre-Production
WM8959
Shut-down and Discharge Sequence
The following sequence describes the register settings required to mute, disable and discharge the
headphone outputs LOUT and ROUT. It assumes that the soft start control and voltage source is
already disabled.
STEP
DESCRIPTION
REGISTER SETTING
1
Enable soft start control and
start-up bias source. Select
start-up bias.
SOFTST = 1
BUFCOPEN = 1
POBCTRL = 1
2
3
Disable VMID
VMID_MODE = 00
Time delay for soft-shutdown to
execute
4
5
Disable Output drivers.
Discharge output drivers.
Select default bias source.
LOUT_ENA = 0
ROUT_ENA = 0
DIS_LOUT = 1
DIS_ROUT = 1
POBCTRL = 0
SOFTST = 0
6
7
Disable soft start control and
soft start voltage.
BUFCOPEN = 0
Table 81 Example Shut-down and Discharge Control Sequence
PP, May 2008, Rev 3.1
123
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
