The devices are designed to be extremely low-power and are based on the high-performance Arm® Cortex®-M4 32-bit RISC core operating at a frequency of up to 64 MHz. This core features a Floating point unit (FPU) single precision that supports all Arm®single-precision data-processing instructions and data types. It also implements a full set of DSP instructions and a memory protection unit (MPU) that enhances application security.

Enhanced inter-processor communication is provided by the IPCC with six bidirectional channels. The HSEM provides hardware semaphores used to share common resources between the two processors.

Direct data transfer between memory and peripherals and from memory to memory is supported by fourteen DMA channels with a full flexible channel mapping by the DMAMUX peripheral.

The devices feature several mechanisms for embedded flash memory and SRAM: readout protection, write protection and proprietary code readout protection. Portions of the memory can be secured for Cortex® -M0+ exclusive access.

The two AES encryption engines, PKA, and RNG enable lower layer MAC and upper layer cryptography. A customer key storage feature may be used to keep the keys hidden.

These devices embed a low-power RTC, one advanced 16-bit timer, one general-purpose32-bit timer, two general-purpose 16-bit timers, and two 16-bit low-power timers.

In addition, up to 18 capacitive sensing channels are available for STM32WB55xx (not on UFQFPN48 package). The STM32WB55xx also embed an integrated LCD driver up to 8x40 or 4x44, with internal step-up converter.

The STM32WB55xx and STM32WB35xx also feature standard and advanced communication interfaces, namely one USART (ISO 7816, IrDA, Modbus, and Smartcard mode), one low- power UART (LPUART), two I2Cs (SMBus/PMBus), two SPIs (one for STM32WB35xx) up to 32 MHz, one serial audio interface (SAI) with two channels and three PDMs, one USB 2.0 FS device with embedded crystal-less oscillator, supporting BCD and LPM and one Quad-SPI with execute-in-place (XIP) capability.

The STM32WB55xx and STM32WB35xx operate in the -40 to +105 °C (+125 °C junction) and -40 to +85 °C (+105 °C junction) temperature ranges from a 1.71 to 3.6 V power supply. A comprehensive set of power-saving modes enables the design of low-power applications.

The STM32WB55xx and STM32WB35xx integrate a high efficiency SMPS step-down converter with automatic bypass mode capability when the VDD falls below VBORx (x = 1, 2, 3, 4) voltage level (default is 2.0 V). It includes independent power supplies for analog input for ADC and comparators, as well as a 3.3 V dedicated supply input for USB.

A VBAT dedicated supply allows the devices to back up the LSE 32.768 kHz oscillator, the RTC and the backup registers, thus enabling the STM32WB55xx and STM32WB35xx to supply these functions even if the main VDD is not present through a CR2032-like battery, a Supercap or a small rechargeable battery.

The STM32WB55xx offer four packages, from 48 to 129 pins. The STM32WB35xx offer one package, 48 pins.

•Radio

2.4 GHz

RF transceiver supporting Bluetooth® 5.4 specification, IEEE 802.15.4-2011 PHY and MAC, supporting Thread 1.3 and Zigbee® 3.0

RX sensitivity: -96 dBm (Bluetooth® Low Energy at 1 Mbps), -100 dBm (802.15.4)

Programmable output power up to +6 dBm with 1 dB steps

Integrated balun to reduce BOM

Support for 2 Mbps

Support GATT caching

Support EATT (enhanced ATT)

Support advertising extension

Dedicated Arm® 32-bit Cortex® M0+ CPU for real-time Radio layer

Accurate RSSI to enable power control

Suitable for systems requiring compliance with radio frequency regulations ETSI EN 300 328, EN 300 440, FCC CFR47 Part 15 and ARIB STD-T66

Support for external PA

Available integrated passive device (IPD) companion chip for optimized matching solution (MLPF-WB-01E3, or MLPF-WB55-02E3, or MLPF-WB-02D3)

•Ultra-low-power platform

1.71 to 3.6 V power supply

– 40 °C to 85 / 105 °C temperature ranges

13 nA shutdown mode

600 nA Standby mode + RTC + 32 KB RAM

2.1 μA Stop mode + RTC + 256 KB RAM

Active-mode MCU: < 53 μA / MHz when RF and SMPS on

Radio: Rx 4.5 mA / Tx at 0 dBm 5.2 mA

•Performance benchmark

1.25 DMIPS/MHz (Drystone 2.1)

219.48 CoreMark® (3.43 CoreMark/MHz at 64 MHz)

•Energy benckmark

303 ULPMark™ CP score

•Supply and reset management

High efficiency embedded SMPS step-down converter with intelligent bypass mode

Ultra-safe, low-power BOR (brownout reset) with five selectable thresholds

Ultra-low-power POR/PDR

Programmable voltage detector (PVD)

VBAT mode with RTC and backup registers

•Clock sources

32 MHz crystal oscillator with integrated trimming capacitors (Radio and CPU clock)

32 kHz crystal oscillator for RTC (LSE)

Internal low-power 32 kHz (±5%) RC (LSI1)

Internal low-power 32 kHz (stability ±500 ppm) RC (LSI2)

Internal multispeed 100 kHz to 48 MHz oscillator, auto-trimmed by LSE (better than ±0.25% accuracy)

High speed internal 16 MHz factory trimmed RC (±1%)

2x PLL for system clock, USB, SAI, ADC

Up to 1 MB flash memory with sector protection (PCROP) against R/W operations, enabling radio stack and application

Up to 256 KB SRAM, including 64 KB with hardware parity check

20x 32-bit backup register

Boot loader supporting USART, SPI, I2C and USB interfaces

OTA (over the air) Bluetooth® Low Energy and 802.15.4 update

Quad SPI memory interface with XIP

1 Kbyte (128 double words) OTP

•Rich analog peripherals (down to 1.62 V)

12-bit ADC 4.26 Msps, up to 16-bit with hardware oversampling, 200 μA/Msps

2x ultra-low-power comparator

Accurate 2.5 V or 2.048 V reference voltage buffered output

•System peripherals

Inter processor communication controller (IPCC) for communication with Bluetooth® Low Energy and 802.15.4

HW semaphores for resources sharing between CPUs

2x DMA controllers (7x channels each) supporting ADC, SPI, I2C, USART, QSPI, SAI, AES, timers

1x USART (ISO 7816, IrDA, SPI Master, Modbus and Smartcard mode)

1x LPUART (low power)

2x SPI 32 Mbit/s

2x I2C (SMBus/PMBus®)

1x SAI (dual channel high quality audio)

1x USB 2.0 FS device, crystal-less, BCD and LPM

Touch sensing controller, up to 18 sensors

LCD 8x40 with step-up converter

1x 16-bit, four channels advanced timer

2x 16-bit, two channels timer

1x 32-bit, four channels timer

2x 16-bit ultra low power timer

1x independent Systick

1x independent watchdog

1x window watchdog

Secure firmware installation (SFI) for Bluetooth® Low Energy and 802.15.4 SW stack

3x hardware encryption AES maximum 256-bit for the application, the Bluetooth® Low Energy and IEEE802.15.4

Customer key storage/manager services

HW public key authority (PKA)

Cryptographic algorithms: RSA, Diffie-Helman, ECC over GF(p)

True random number generator (RNG)

Sector protection against R/W operation (PCROP)

CRC calculation unit

Die information: 96-bit unique ID

IEEE 64-bit unique ID, possibility to derive 802.15.4 64-bit and Bluetooth® Low Energy 48-bit EUI

•Up to 72 fast I/Os, 70 of them 5 V-tolerant

•Development support

Serial wire debug (SWD), JTAG for the application processor

Application cross trigger with input / output

Embedded Trace Macrocell™ for application

•ECOPACK2 compliant packages