STM32L552CCT3PTR datasheet(62/340 Pages) STMICROELECTRONICS

62 / 340 page

Functional overview

STM32L552xx

62/340

DS12737 Rev 6

3.21.2

Internal voltage reference (VREFINT)

The internal voltage reference (VREFINT) provides a stable (bandgap) voltage output for

the ADC and the comparators. The VREFINT is internally connected to the ADC1_IN0 input

channel. The precise voltage of VREFINT 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.

3.21.3

VBAT battery voltage monitoring

This embedded hardware enables the application to measure the VBAT battery voltage using

the internal ADC channel ADC1_IN18. As the VBAT voltage may be higher than the VDDA,

and thus outside the ADC input range, the VBAT pin is internally connected to a bridge

divider by 3. As a consequence, the converted digital value is one third of the VBAT voltage.

Table 14. 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),

VDDA = VREF+ = 3.0 V (± 10 mV)

0x0BFA 05A8 - 0x0BFA 05A9

TS_CAL2

TS ADC raw data acquired at a

temperature of 130 °C (± 5 °C),

VDDA = VREF+ = 3.0 V (± 10 mV)

0x0BFA 05CA- 0x0BFA 05CB

Table 15. Internal voltage reference calibration values

Calibration value name

Description

Memory address

VREFINT

Raw data acquired at a

temperature of 30 °C (± 5 °C),

VDDA = VREF+ = 3.0 V (± 10 mV)

0x0BFA 05AA - 0x0BFA 05AB

STM32L552CCT3PTR Datasheet(PDF) 62 Page - STMicroelectronics