Brownout Reset (Bor); Programmable Voltage Detector (Pvd); Figure 13. Bor Thresholds - STMicroelectronics STM32F405 Reference Manual

RM0090
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.
When the supply voltage (V
generated.
The BOR can be disabled by programming the device option bytes. In this case, the
power-on and power-down is then monitored by the POR/ PDR (see
on reset (POR)/power-down reset
The BOR threshold hysteresis is ~100 mV (between the rising and the falling edge of the
supply voltage).
5.2.3

Programmable voltage detector (PVD)

You can use the PVD to monitor the V
selected by the PLS[2:0] bits in the
STM32F405xx/07xx and STM32F415xx/17xx
threshold.
BOR
) drops below the selected V
DD
(PDR)).

Figure 13. BOR thresholds

power supply by comparing it to a threshold
DD
PWR power control register (PWR_CR) for
and
DocID018909 Rev 11
Power controller (PWR)
threshold, a device reset is
BOR
Section 5.2.1: Power-
PWR power control register (PWR_CR)
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