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STM32F3xx microcontroller low-power overview

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Note:

For more details about the power supply, you can refer to the reference manuals RM00313,

RM0316, RM0364, RM0365, RM0366 and to the relevant datasheets available from the

STMicroelectronics web site.

1.2

Power mode features

By default, after power-on or system reset, the STM32F3xx microcontrollers are in Run

mode. This is a fully active mode that consumes much power even when performing minor

tasks.

Highly optimized low-power modes are integrated to save power when the CPU does not

need to be kept running, thus allowing to achieve the best compromise between a low-

power consumption, a short startup time and available wakeup sources in the application

design.

This part describes the different low-power modes available in STM32F3xxxx devices and

the related features.

STM32F3xxxx devices feature four main low-power modes:

•

Sleep mode:

–

Only the CPU clock is stopped.

–

current consumption increases with the clock frequency. As in a Run mode, the

user needs to know the system clock configuration rules.

•

Stop mode

–

The lowest power consumption while all the SRAM and registers are kept.

–

PLL, HSI, HSE are disabled.

–

All clocks in 1.8 V domain are switched off.

–

Voltage regulator is working in normal mode or low-power modes.

Stop mode achieves the lowest power consumption while retaining the content of SRAM

and registers. All clocks in the 1.8 V domain are stopped, the PLL, the HSI and the HSE are

disabled. The voltage regulator can also be put either in normal or in low-power modes (not

available when internal regulator is off).

Table 2. STM32F3xxxx device power supply considerations

Internal regulator

status

Power domain considerations

Voltage regulator ON

From 2V to 3.6V

From 2V to 3.6V

•

•

when DAC and

OPAMP are used.

•

when ADC is

used.

No

considerations

Voltage regulator OFF

1.8V ± 8%

From 1.65V to 3.6V

•

POR, PDR and

PVD features are

not available.

•

Standby mode is

not available.