STM32F105xx, STM32F107xx
Description
2.3.9
Power supply schemes
●
V
= 2.0 to 3.6 V: external power supply for I/Os and the internal regulator.
DD
Provided externally through V pins.
DD
●
V
, V
= 2.0 to 3.6 V: external analog power supplies for ADC, Reset blocks, RCs
DDA
SSA
and PLL (minimum voltage to be applied to V
is 2.4 V when the ADC is used). V
DDA
DDA
and V
must be connected to V and V , respectively.
SSA
DD SS
●
V
= 1.8 to 3.6 V: power supply for RTC, external clock 32 kHz oscillator and backup
BAT
registers (through power switch) when V is not present.
DD
2.3.10
Power supply supervisor
The device has an integrated power-on reset (POR)/power-down reset (PDR) circuitry. It is
always active, and ensures proper operation starting from/down to 2 V. The device remains
in reset mode when V is below a specified threshold, V
, without the need for an
DD
POR/PDR
external reset circuit.
The device features an embedded programmable voltage detector (PVD) that monitors the
/V power supply and compares it to the V threshold. An interrupt can be
V
DD DDA
PVD
generated when V /V
drops below the V
threshold and/or when V /V
is higher
DD DDA
PVD
DD DDA
than the V
threshold. The interrupt service routine can then generate a warning
PVD
message and/or put the MCU into a safe state. The PVD is enabled by software.
2.3.11
Voltage regulator
The regulator has three operation modes: main (MR), low power (LPR) and power down.
●
●
●
MR is used in the nominal regulation mode (Run)
LPR is used in the Stop modes.
Power down is used in Standby mode: the regulator output is in high impedance: the
kernel circuitry is powered down, inducing zero consumption (but the contents of the
registers and SRAM are lost)
This regulator is always enabled after reset. It is disabled in Standby mode.
2.3.12
Low-power modes
The STM32F105xx and STM32F107xx connectivity line supports three low-power modes to
achieve the best compromise between low power consumption, short startup time and
available wakeup sources:
●
Sleep mode
In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can
wake up the CPU when an interrupt/event occurs.
●
Stop mode
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 RC
and the HSE crystal oscillators are disabled. The voltage regulator can also be put
either in normal or in low-power mode.
The device can be woken up from Stop mode by any of the EXTI line. The EXTI line
source can be one of the 16 external lines, the PVD output, the RTC alarm or the USB
OTG FS wakeup.
Doc ID 15274 Rev 6
15/104
STMICROELECTRONICS [ ST ]
