STMicroelectronics Introduces Entry-Level MCU Series for Smart Devices

STMicroelectronics has announced the STM32C5, a new series of microcontrollers (MCUs) aimed squarely at cost-sensitive embedded applications that have traditionally used Cortex-M0 or Cortex-M23 cores. The new parts pair an Arm Cortex-M33 core with ST’s proprietary 40 nm manufacturing process. This combination brings a meaningful performance jump while keeping prices low enough to target smart thermostats, electronic door locks, wearables, industrial sensors, robotic actuators, and computer peripherals.

ST’s STM32C5 series MCUs are powered by an Arm Cortex-M33 embedded processor and ST’s 40 nm manufacturing process. Image used courtesy of STMicroelectronics

STM32C5 Entry-Level MCUs

The STM32C5 MCUs leverage ST’s proprietary 40 nm manufacturing process, which is cost-efficient, supports higher clock speeds, and enables flash densities above 512 KB. The result is a core that runs at 144 MHz and scores 593 CoreMark, which ST says is roughly three times what you’d expect from a typical Cortex-M0+ device at a comparable price point.

On-chip flash ranges from 128 KB to 1 MB, and the 40 nm node makes Cortex-M33 performance accessible at an attractive price for entry-level applications that were previously limited to lower-performing Cortex-M0 and Cortex-M23 devices. SRAM ranges from 64 KB to 256 KB, depending on the variant, giving designers noticeably more headroom than is typical at this price tier.

The STM32C5’s dynamic power consumption is under 80 µA/MHz. The power supply architecture uses a single LDO regulator, freeing up extra I/O pins — a small but welcome detail in pin-constrained designs. An on-chip DMA controller with two instances, each with at least four channels, allows two fetches in parallel, helping developers boost application performance while simplifying software. A 1% calibrated RC oscillator operating across -20°C to 105°C means many designs can skip an external crystal entirely.

A look at ST’s STM32C5 MCU product portfolio. Image used courtesy of STMicroelectronics

Connectivity and Security

The peripheral set punches above what the price suggests. Higher-end variants include 10/100 Mbit Ethernet, two FDCAN interfaces, USB, and OctoSPI. The series is available in packages ranging from 20 to 144 pins, starting at 3×3 mm, and is rated for operation from -40°C to 125°C.

Security is a notable focus for the series. The MCUs target SESIP3 and PSA Level 3 certifications, with memory protection, tamper protection, cryptographic engines including AES and hashing algorithms, and temporal isolation to protect processes such as secure boot and firmware update. The top-tier STM32C5A3 variant adds a hardware unique key and side-channel-attack-protected PKA and AES engines.

Users can begin prototyping STM32C5 MCUs with ST’s STM32 Nucleo-64 development board. Image used courtesy of STMicroelectronics

Ecosystem and Availability

The STM32C5 is supported by STM32Cube updates, including STM32CubeMX2, HAL2, STM32CubeIDE options, middleware ports, and example libraries, providing production-grade drivers and code-size-optimized libraries to speed development. Optimized ports of popular middleware, including FreeRTOS, LwIP, USBX, and FileX, are part of the package. ST describes the STM32C5 as the first series to leverage an evolution of the STM32Cube ecosystem, which remains freely available.

Three Nucleo evaluation boards are now available, including the NUCLEO-C542RC, NUCLEO-C562RE, and NUCLEO-C5A3ZG, alongside a display extension board from Riverdi, paired with TouchGFX, for designers who need a GUI at this price point.

STM32C5 MCUs are now entering production, in packages ranging from the 3 mm × 3 mm UFQFPN20 to the 20 mm × 20 mm LQFP144. Prices start at $0.64 for orders of 10,000 units. The full product lineup spans nine sub-families from the STM32C531 through the STM32C5A3, covering a range of flash, SRAM, connectivity, and security options.