Functional overview
STM32F038x6
16/102
DocID026079 Rev 3
An analog watchdog feature allows very precise monitoring of the converted voltage of one,
some or all selected channels. An interrupt is generated when the converted voltage is
outside the programmed thresholds.
3.10.1 Temperature
sensor
The temperature sensor (TS) generates a voltage V
SENSE
that varies linearly with
temperature.
The temperature sensor is internally connected to the ADC_IN16 input channel which is
used to convert the sensor output voltage into a digital value.
The sensor provides good linearity but it has to be calibrated to obtain good overall
accuracy of the temperature measurement. As the offset of the temperature sensor 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, accessible in read-only mode.
3.10.2
Internal voltage reference (V
REFINT
)
The internal voltage reference (V
REFINT
) provides a stable (bandgap) voltage output for the
ADC. V
REFINT
is internally connected to the ADC_IN17 input channel. The precise voltage
of V
REFINT
is individually measured for each part by ST during production test and stored in
the system memory area. It is accessible in read-only mode.
3.10.3 V
BAT
battery voltage monitoring
This embedded hardware feature allows the application to measure the V
BAT
battery voltage
using the internal ADC channel ADC_IN18. As the V
BAT
voltage may be higher than V
DDA
,
and thus outside the ADC input range, the V
BAT
pin is internally connected to a bridge
divider by 2. As a consequence, the converted digital value is half the V
BAT
voltage.
Table 3. Temperature sensor calibration values
Calibration value name
Description
Memory address
TS_CAL1
TS ADC raw data acquired at a
temperature of 30 °C (
±
5 °C),
V
DDA
= 3.3 V (
±
10 mV)
0x1FFF F7B8 - 0x1FFF F7B9
TS_CAL2
TS ADC raw data acquired at a
temperature of 110 °C (
±
5 °C),
V
DDA
= 3.3 V (
±
10 mV)
0x1FFF F7C2 - 0x1FFF F7C3
Table 4. Internal voltage reference calibration values
Calibration value name
Description
Memory address
VREFINT_CAL
Raw data acquired at a
temperature of 30 °C (
±
5 °C),
V
DDA
= 3.3 V (
±
10 mV)
0x1FFF F7BA - 0x1FFF F7BB
