DocID029918 Rev 1 17/48
AN4938 Power supplies
47
Figure 9. NRST circuitry timing example
1.3.7 Bypass mode
The power management unit can be bypassed. This feature can be configured by software.
When bypassed, the core power supply should be provided through VCAPx
pins connected
together.
In Bypass mode, the internal voltage scaling is not managed internally, and the external
voltage value (1.0 to 1.2
V) must be consistent with the targeted maximum frequency (see
datasheet for the actual VOS level).
It can be lowered to 0.7 to 1.0 V in Stop mode (see datasheet for the actual SVOS level).
In Standby mode the external source will be switched off and the V
CORE
domains powered
down. The external source will be switched on when exiting Standby mode.
In Bypass mode, the external voltage must be present before or at the same time as V
DD
. To
avoid conflict with the LDO, the external voltage must be kept above 1.15
V until the LDO is
disabled by software.
2SHUDWLRQ 3RZHU'RZQSKDVH3RZHU2QSKDVH
069
9''
WLPH
9
9''GXULQJRSHUDWLRQNHSWDERYH9
WLPH
1567
1567.HSWORZE\
LQWHUQDOFLUFXLWU\
9''
5HVHWE\
LQWHUQDO
VRXUFHV
1567IRUFHGORZE\H[WHUQDO
VXSHUYLVRU
VXSHUYLVRU
ORZWULSSRLQW
VXSHUYLVRU
KLJKWULSSRLQW
1567.HSWORZE\
H[WHUQDOVXSHUYLVRU
7
5677(032
7
VXSHUYLVRU
7
VXSHUYLVRU!
7
5677(032
7
VXSHUYLVRU
7
5677(032
To Next Page
Loading...
Need help?
General
