Power Supply Supervisor; Power-On Reset (Por)/Power-Down Reset (Pdr); Brownout Reset (Bor); Figure 9. Power-On Reset/Power-Down Reset Waveform - ST STM32F423 Reference Manual

Power controller (PWR)
Note: For more details, refer to the voltage regulator section in the STM32F413/423 datasheet.
5.2

Power supply supervisor

5.2.1

Power-on reset (POR)/power-down reset (PDR)

The device has an integrated POR/PDR circuitry that allows proper operation starting
from 1.8 V.
To use the device below 1.8 V, the internal power supervisor must be switched off using the
PDR_ON pin (please refer to section Power supply supervisor of the STM32F413/423
datasheet). The device remains in Reset mode when V
threshold, V
concerning the power on/power-down reset threshold, refer to the electrical characteristics
of the datasheet.
5.2.2

Brownout reset (BOR)

During power on, the Brownout reset (BOR) keeps the device under reset until the supply
voltage reaches the specified V
V is configured through device option bytes. By default, BOR is off. 3 programmable
BOR
V threshold levels can be selected:
BOR
•
BOR Level 3 (VBOR3). Brownout threshold level 3.
•
BOR Level 2 (VBOR2). Brownout threshold level 2.
•
BOR Level 1 (VBOR1). Brownout threshold level 1.
Note: For full details about BOR characteristics, refer to the "Electrical characteristics" section in
the device datasheet.
98/1324
, without the need for an external reset circuit. For more details
POR/PDR

Figure 9. Power-on reset/power-down reset waveform

BOR
RM0430 Rev 8
DD
threshold.
/V is below a specified
DDA
RM0430