STMicroelectronics STM32U073CBU6

Overview

STM32U073CBU6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller operating up to 56 MHz, featuring 256-Kbyte flash memory, 40-Kbyte SRAM with hardware parity, and integrated USB 2.0 full-speed crystal-less interface. It delivers 407 ULPMark™-CP and supports VBAT mode at 130 nA with RTC and 9×32-bit backup registers - ideal for battery-powered IoT sensors and portable medical devices.

For engineers reviewing the STM32U073CBU6 datasheet, STM32U073CBU6 pinout, STM32U073CBU6 application, or STM32U073CBU6 equivalent, key selection criteria include its 16 nA shutdown current, 4 μs wake-up from Stop mode, 12-bit ADC with 0.4 µs conversion, LCD driver (8×48 segments), and dual 5 V-tolerant I/O banks enabling direct interface with legacy logic and industrial sensors.

Technical Context

The STM32U073CBU6 integrates an ART Accelerator enabling 0-wait-state execution from flash at 56 MHz, paired with a 16 MHz factory-trimmed HSI oscillator (±1%) and auto-trimmed multispeed MSI (±0.25%). Its power architecture separates VCORE, VDDA (1.62–3.6 V), VDDUSB (3.0–3.6 V), and VBAT domains to isolate analog precision and RTC retention.

It implements a 32-bit multi-AHB bus matrix, memory protection unit (MPU), and dual-domain clock tree supporting simultaneous operation of USB, RTC, and low-power timers in Stop 2 mode (695 nA without RTC). Security includes RDP Level 2, HDP, secure boot, and NIST SP 800-90B–candidate TRNG.

Key Specifications

Pinout & Package

STM32U073CBU6 is housed in a 48-pin UFQFPN package (7 × 7 mm, 0.5 mm pitch), RoHS-compliant and ECOPACK2 certified. Pin layout supports dual VDDIO banks, dedicated VDDA/VSSA analog supply, VBAT backup domain, and USB DP/DM routing with ESD protection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power Arm Cortex-M0+ microcontroller applications.

Compared with STM32L073RZT6 and RA2E2A00GJF#AC0, the STM32U073CBU6 uniquely combines crystal-less USB, LCD driver, and sub-20 nA shutdown - making it the only option for compact, battery-powered USB-rechargeable displays with tamper-resistant firmware.

Availability

STM32U073CBU6 is available at Aetrix Electronics and suitable for smart utility metering, portable medical sensors, industrial wireless nodes, and smart home display panels requiring stable component supply across extended product lifecycles.

Supply support for STM32U073CBU6 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power management ICs, sensors, and automotive chips since 1987.

The STM32U0 series targets ultra-low-power, cost-sensitive edge devices demanding long battery life, integrated human interface (LCD/touch), and secure USB connectivity - bridging the gap between legacy 8-bit MCUs and mainstream Cortex-M3/M4 solutions.

FAQ

What is the maximum operating temperature range for STM32U073CBU6?

The STM32U073CBU6 is rated for ambient operation from –40 °C to +125 °C, with junction temperature up to +130 °C. This rating is validated per DS14548 Rev 2 and applies to all ultra-low-power modes including VBAT and Shutdown, enabling deployment in automotive under-hood or industrial motor-control environments.

Does STM32U073CBU6 support USB device enumeration without an external crystal?

Yes - it integrates a crystal-less USB 2.0 full-speed PHY with internal 48 MHz clock recovery, eliminating the need for an external 48 MHz crystal or oscillator. The USB interface achieves <0.25% frequency accuracy using the LSE-trimmed MSI oscillator, meeting USB specification requirements for enumeration and data transfer.

How many GPIOs are available in the UFQFPN48 package, and which are 5 V-tolerant?

The STM32U073CBU6 in UFQFPN48 provides 42 GPIOs, of which 39 are 5 V-tolerant (all except those in the VDDA/VSSA and analog-dedicated pins). This allows direct interfacing with 5 V logic, industrial sensors, and legacy peripherals without level shifters - confirmed in Table 1 and pinout diagrams of DS14548 Rev 2.

Can the internal voltage reference buffer (VREFBUF) be used with the 12-bit ADC?

Yes - the VREFBUF generates either 2.048 V or 2.5 V output (configurable via VRS bit), and this voltage can be routed to VREF+ to serve as the ADC's reference. When enabled, it replaces external reference ICs and improves ADC accuracy stability over temperature, provided VDDA ≥ 2.4 V (for 2.048 V) or ≥ 2.8 V (for 2.5 V).