STM32L452XX Datasheet, PDF (21/210 Pages) STMicroelectronics – Ultra-low-power with FlexPowerControl

STM32L452xx
Functional overview
Note:
Note:
If these supplies are tied to ground, the I/Os supplied by these power supplies are not 5 V
tolerant.
V_DDIOx is the I/Os general purpose digital functions supply. V_DDIOx represents V_DDIO1, with
V_DDIO1 = V_DD.
Figure 2. Power supply overview
9_''$
9_66$
9''$GRPDLQ
$'FRQYHUWHUV
&RPSDUDWRUV
'$FRQYHUWHUV
2SHUDWLRQDODPSOLILHUV
9ROWDJHUHIHUHQFHEXIIHU
9_''86%
9₆₆
9_''
9₆₆
9_''
86%WUDQVFHLYHUV
9''GRPDLQ
9'',2
,2ULQJ
5HVHWEORFN
7HPSVHQVRU
3//+6,06,+6,
6WDQGE\FLUFXLWU\
:DNHXSORJLF,:'*
9ROWDJHUHJXODWRU
9&25(
9&25(GRPDLQ
&RUH
0HPRULHV
'LJLWDOSHULSKHUDOV
3.9.2
9_%$7
/RZYROWDJHGHWHFWRU
%DFNXSGRPDLQ
/6(FU\VWDO.RVF
%.3UHJLVWHUV
5&&%'&5UHJLVWHU
57&
06Y9
Power supply supervisor
The device has an integrated ultra-low-power brown-out reset (BOR) active in all modes
except Shutdown and ensuring proper operation after power-on and during power down.
The device remains in reset mode when the monitored supply voltage V_DD is below a
specified threshold, without the need for an external reset circuit.
The lowest BOR level is 1.71V at power on, and other higher thresholds can be selected
through option bytes.The device features an embedded programmable voltage detector
(PVD) that monitors the V_DD power supply and compares it to the VPVD threshold. An
interrupt can be generated when V_DD drops below the VPVD threshold and/or when V_DD is
higher than the VPVD threshold. The interrupt service routine can then generate a warning
message and/or put the MCU into a safe state. The PVD is enabled by software.
In addition, the device embeds a Peripheral Voltage Monitor which compares the
independent supply voltage V_DDA with a fixed threshold in order to ensure that the
peripheral is in its functional supply range.
DocID029968 Rev 2
21/210
55