Datasheet

DocID030538 Rev 3 21/226
STM32H743xI Functional overview
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3.5.2 Power supply supervisor
The devices have an integrated power-on reset (POR)/ power-down reset (PDR) circuitry
coupled with a Brownout reset (BOR) circuitry:
• Po
wer-on reset (POR)
The POR supervisor monitors V
DD
power supply and compares it to a fixed threshold.
The devices remain in reset mode when V
DD
is below this threshold,
• Power-down reset (PDR)
The PDR supervisor monitors V
DD
power supply. A reset is generated when V
DD
drops
below a fixed threshold.
The PDR supervisor can be enabled/disabled through PDR_ON pin.
• Brownout reset (BOR)
The BOR supervisor monitors V
DD
power supply. Three BOR thresholds (from 2.1 to
2.7 V) can be configured through option bytes. A reset is generated when V
DD
drops
below this threshold.
3.5.3 Voltage regulator
The same voltage regulator supplies the 3 power domains (D1, D2 and D3). D1 and D2 can
be independently switched off.
Voltage regulator output can be adjusted according to application needs through 5 power
supply levels:
• Run mo
de (VOS1 to VOS3)
– Scale 1: high performance
– Scale 2: medium performance and consumption
– Scale 3: optimized performance and low-power consumption
• Stop mode (SVOS3 to SVOS5)
– Scale 3: peripheral with wakeup from stop mode capabilities (UART, SPI, I2C,
LPTIM) are operational
– Scale 4 and 5 where the peripheral with wakeup from Stop mode is disabled
The peripheral functionality is disabled but wakeup from Stop mode is possible
through GPIO or asynchronous interrupt
.
3.6 Low-power strategy
There are several ways to reduce power consumption on STM32H743xI:
• Decrease
dynamic power consumption by slowing down the system clocks even in
Run mode and individually clock gating the peripherals that are not used.
• Save power consumption when the CPU is idle, by selecting among the available low-
power mode according to the user application needs. This allows achieving the best
compromise between short startup time, low-power consumption, as well as available
wakeup sources.
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