wm8351 Wolfson Microelectronics plc, wm8351 Datasheet - Page 135

• Manufacturer Part Number: wm8351
• Description: Wolfson Audioplus? Stereo Codec With Power Management
• Manufacturer: Wolfson Microelectronics plc

Production Data
w
for LDO2
R207 (CFh)
for LDO3
R210 (D2h)
for LDO4
Note: n is a number between 1 and 4 that identifies the individual LDO regulator
Table 81 Enabling and Disabling the LDO Regulators
14.7.2
The LDO Regulators can be configured to operate in different modes using the register bits
described in Table 82.
In Switch mode, the Regulators operate as current-limited switches with no voltage regulation.
In LDO Regulator mode, the Regulators generate an output voltage determined by the LDOn_VSEL
fields. The LDO Regulators are dynamically programmable - the output voltage may be adjusted in
software at any time. The Regulators are critically damped to ensure there is no voltage overshoot or
undershoot when adjusting the output voltage.
The default output voltage for the LDO Regulators is set by writing to the LDOn_VSEL register bits.
The ‘image’ voltage settings LDOn_VIMG are alternate values that may be invoked when the
HIBERNATE software or hardware control is asserted.
R200 (C8h)
for LDO1
R203 (CBh)
for LDO2
R206 (CEh)
for LDO3
R209 (D1h)
for LDO4
R202 (CAh)
for LDO1
R205 (CDh)
for LDO2
R208 (D0h)
for LDO3
R211 (D3h)
for LDO4
Note: n is a number between 1 and 4 that identifies the individual LDO regulator
Table 82 Controlling Regulator Voltage and Switch Mode
The LDO Regulators can also be controlled by the device HIBERNATE bit, or by hardware input
signals L_PWR1, L_PWR2 and L_PWR3. Several GPIO pins can be assigned as L_PWR pins. Each
ADDRESS
LDO REGULATOR CONTROL
4:0
4:0
BIT
14
9:6
LDOn_SWI
LDOn_VSEL
[4:0]
LDOn_VIMG
[4:0]
LDOn_SDSL
OT [3:0]
LABEL
Dependant on
CONFIG[1:0]
DEFAULT
settings
1 1100
0000
0
1110 = Start-up in time slot 14
1111 = Start up on entering ACTIVE
Time slot for LDOn shutdown.
0000 = Shut down on entering OFF
0001 = Shutdown in time slot 1
…. (total 14 slots available)
1110 = Shutdown in time slot 14
1111 = Shut down on entering OFF
LDOn Regulator mode
0 = LDO voltage regulator
1 = Current-limited switch (no voltage
LDOn Regulator output voltage (when
LDOn_SWI=0)
1 1111 = 3.3V
… (100mV steps)
1 0000 = 1.8V
0 1111 = 1.65V
… (50mV steps)
0 0000 = 0.9V
LDOn Regulator output image voltage
1 1111 = 3.3V
… (100mV steps)
1 0000 = 1.8V
0 1111 = 1.65V
… (50mV steps)
0 0000 = 0.9V
regulation, LDOn_VSEL has no
effect)
DESCRIPTION
PD, June 2009, Rev 4.1
WM8351
135