Production Data
WM8326
30.4 LDO REGULATOR EXTERNAL COMPONENTS
The recommended connections to the LDO Regulators are illustrated in Figure 31.
1.5V – 5.5V
LDO1VDD
CIN
WM8326
LDO1
LDO1VDD may be connected to PVDD or to
one of the DC-DC buck converter outputs.
LDO1VOUT
COUT
VO
The LDO input supply must not exceed PVDD.
Load
Note: Equivalent circuit applies for LDO2 through to LDO10.
Figure 31 LDO Regulators External Components
When selecting suitable capacitors, is it imperative that the effective capacitance is within the
required limits at the applicable input/output voltage of the converter. Ceramic X7R or X5R types are
recommended.
Wolfson recommends the following external components for use with LDO Regulators 1 to 6.
COMPONENT
VALUE
2.2μF
PART NUMBER
SIZE
0402
0402
COUT
CIN
Kemet C0402C225M9PAC
MuRata GRM155R61A105KE15
1.0μF
Table 88 Recommended External Components - LDO1 to LDO6
Wolfson recommends the following external components for use with LDO Regulators 7 to 10. For
these regulators, note that it is important that the output capacitance, COUT, does not exceed 4.7F.
COMPONENT
VALUE
1.0μF
PART NUMBER
SIZE
0402
0402
COUT
CIN
MuRata GRM155R61A105KE15
MuRata GRM155R61A105KE15
1.0μF
Table 89 Recommended External Components - LDO7 to LDO10
Wolfson recommends the following external components for use with LDO Regulators 11 to 13.
COMPONENT
COUT (LDO11)
COUT (LDO12)
COUT (LDO13)
VALUE
0.1μF
0.1μF
2.2μF
PART NUMBER
SIZE
0201
0201
0402
MuRata GRM033R60J104KE19
MuRata GRM033R60J104KE19
Kemet C0402C225M9PAC
Table 90 Recommended External Components - LDO11 to LDO13
PD, June 2012, Rev 4.0
251
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
