STM32WB55 datasheet(47/193 Pages) STMICROELECTRONICS

47 / 193 page

DS11929 Rev 11

47/193

STM32WB55xx STM32WB35xx

Functional overview

3.15

Voltage reference buffer (VREFBUF)

The STM32WB55xx devices embed a voltage reference buffer that can be used as voltage

reference for the ADC and also as voltage reference for external components through the

VREF+ pin. The internal voltage reference buffer supports two voltages:



2.048 V



2.5 V

An external voltage reference can be provided through the VREF+ pin when the internal

voltage reference buffer is off. The VREF+ pin is double-bonded with VDDA on UFQFPN48

package, hence the internal voltage reference buffer is not available on a dedicated pin, but

user can still use the VDDA value.

3.16

Comparators (COMP)

The STM32WB55xx and STM32WB35xx devices embed two rail-to-rail comparators with

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

low-power) and with selectable output polarity.

The reference voltage can be one of the following:



External I/O



Internal reference voltage or submultiple (1/4, 1/2, 3/4).

All comparators can wake up from Stop mode, generate interrupts and breaks for the timers

and can be also combined into a window comparator.

3.17

Touch sensing controller (TSC)

The touch sensing controller provides a simple solution for adding capacitive sensing

functionality to any application. Capacitive sensing technology is able to detect finger

presence near an electrode which is protected from direct touch by a dielectric such as

glass or plastic. The capacitive variation introduced by the finger (or any conductive object)

is measured using a proven implementation based on a surface charge transfer acquisition

principle.

The touch sensing controller is fully supported by the STMTouch touch sensing firmware

library (free to use) and enables reliable touch sensing functionality in the end application.

STM32WB55 Datasheet(PDF) 47 Page - STMicroelectronics