Datasheet

DocID030538 Rev 3 29/226
STM32H743xI Functional overview
46
In addition, an analog watchdog feature can accurately monitor the converted voltage of
one, some or all selected channels. An interrupt is generated when the converted voltage is
outside the programmed thresholds.
To synchronize A/D conversion and timers, the ADCs could be triggered by any of TIM1,
TIM2, TIM3, TIM4, TIM6, TIM8, TIM15, HRTIM1 and LPTIM1 timer.
3.18 Temperature sensor
STM32H743xI devices embeds a temperature sensor that generates a voltage (V
TS
) that
varies linearly with the temperature. This temperature sensor is internally connected to
ADC3_IN18. The conversion range is between 1.7 V and 3.6 V. It can measure the device
ambient temperature ranging from − 40 to +125 °C with a precision of +-2%.
The temperature sensor have a good linearity, but it has to be calibrated to obtain a good
ov
erall accuracy of the temperature measurement. As the temperature sensor offset varies
from chip to chip due to process variation, the uncalibrated internal temperature sensor is
suitable for applications that detect temperature changes only. To improve the accuracy of
the temperature sensor measurement, each device is individually factory-calibrated by ST.
The temperature sensor factory calibration data are stored by ST in the System memory
area, which is accessible in read-only mode.
3.19 V
BAT
operation
The V
BAT
power domain contains the RTC, the backup registers and the backup SRAM.
To optimize battery duration, this p
ower domain is supplied by V
DD
when available or by the
voltage applied on VBAT pin (when V
DD
supply is not present). V
BAT
power is switched
when the PDR detects that V
DD
dropped below the PDR level.
The voltage on the VBAT pin could be provided by a
n external battery, a supercapacitor or
directly by V
DD
, in which case, the V
DD
mode is not functional.
V
BAT
operation is activated when V
DD
is not present.
The V
BAT
pin supplies the RTC, the backup registers and the backup SRAM.
Note: When the microcontroller is supplied from V
BAT
, external interrupts and RTC alarm/events
do not exit it from V
BAT
operation.
When PDR_ON pin is connected to V
SS
(Internal Reset OFF), the V
BAT
functionality is no
more available and V
BAT
pin should be connected to VDD.
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