STM32WBA62CI datasheet(50/185 Pages) STMICROELECTRONICS

50 / 185 page

Functional overview

STM32WBA6xxx

50/185

DS14736 Rev 1

3.20.2

Internal voltage reference (VREFINT)

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

ADC and comparators. The VREFINT is internally connected to ADC4 input channel that is

used to convert the voltage into a digital value.

The precise voltage of VREFINT is individually measured for each part by

STMicroelectronics during production test and stored in the system memory area. It is

accessible in read-only mode.

3.21

Voltage reference buffer (VREFBUF)

The devices embed a voltage reference buffer (VREFBUF) that can be used as voltage

reference for the ADC and external components through the VREF+ pin.

Figure 7. VREFBUF block diagram

The internal VREFBUF supports four voltages between 1.5 and 2.5 V, for more information

see VREFBUF characteristics.

When the VREFBUF is disabled, an external voltage reference can be provided through the

VREF+ pin.

3.22

Comparators (COMP)

The devices embed two rail-to-rail comparators, COMP1 and COMP2, with programmable

reference voltage (internal or external), hysteresis and speed (low-speed for low-power) and

with selectable output polarity.

Table 15. Internal voltage reference calibration values

Calibration

value name

Description

Memory address

VREFINT_CAL

Internal voltage reference ADC4 12-bit raw data

acquired at (30 ± 5) °C, VDDA = 3.0 V (± 10 mV)

0x0BFA 07A5 - 0x0BFA 07A6

MSv64430V2

VREFINT

VREF+

VSSA

STM32WBA62CI Datasheet(PDF) 50 Page - STMicroelectronics