STMicroelectronics Unveils the STM32G4 Series of Microcontrollers

May 30, 2019 by Gary Elinoff

ST's new MCUs target applications in e-mobility, digital power supplies, motor control, lighting, and building automation.

ST's new MCUs target applications in e-mobility, digital power supplies, motor control, lighting, and building automation.

The new series of STM32G4 MCUs live up to the challenge of managing a new generation of smart electronic products built on sensor-driven features and based on the new energy-saving silicon carbide and gallium nitride power technologies.


The STM32G4. All images from STMicroelectronics


Additional  with 12 independent channels featuring 184 ps resolution, with compensation for temperature and voltage drift

Up to 512Kbyte Flash memory with error code correction (ECC)

Information on reference device STM32G431K6U6 can be found here, and information on other members of the STM32G4 series can found be found here.


Arm Cortex-M4 Core

Members of the STM32G4 series are built on the solid foundation of the STM32F3 series. According to STMicro's press release on the MCUs, the company's General Manager of the Microcontroller Division, Ricardo De Sa Earp, says that the new series “integrates rich, enhanced peripherals and interfaces with the industry-standard Arm core."

The MCUs series is built on the Arm Cortex-M4 core, specifically a high-speed implementation of that core (170MHz).

Member devices feature hardware-based mathematical accelerators designed to boost performance and efficiency. Most importantly, the energy-stingy units use than 165µA/MHz in run mode.

Offloading the Core Processor

Member devices include a filter-math accelerator (FMAC) and a dedicated CORDIC (Coordinate Rotation Digital Computer) engine. They make possible faster results for:

  • Rotational and vector trigonometry calculation used in motor control
  • Logarithmic, hyperbolic, and exponential functions
  • Filtering for signal conditioning and digital power control

These new features build on already the extant ART Accelerator, which enhances dynamic and static memory-cache performance, and the CCM-SRAM Routine Booster for performance and power efficiency.

These hardware-based mechanisms can get results more quickly and efficiently than can the main processor can. This offloading also frees the core to receive and process more sensor data and control additional user functions.

Hardware-based Cybersecurity

Cybersecurity is on everyone’s mind these days and these MCUs aim to empower developers to build it into the very guts of their products. While the MCUs are equipped to receive industry-standard live firmware updates, ST made efforts to "reduce threat surfaces" by effectively locking debug access after initial programming. Additionally, the units utilize AES-256 encryption and have a securable memory area for said firmware upgrades and storage.

Analog Peripherals

STMicro is presenting the new MCUs as being suitable for "analog-rich applications"—a term that presumably refers to situations wherein analog is preferable to digital.

The various members of the STM32G4 series support up to 25 analog peripherals, including:

  • Up to five 12-bit 4M sample/sec analog-to-digital converter (ADC) with hardware oversampling able to achieve 16-bit resolution.
  • Up to six high-speed, high gain-bandwidth op-amps with 1% built-in gain
  • Up to seven 12-bit 15 Msample/sec DACs

Additional Features

  • Run mode power: Less than 165µA/MHz 
  • On-chip RAM: Up to 128Kbyte with parity bit
  • Memory: Up to 512Kbyte Flash memory with error code correction (ECC)

Eval Boards and Kits

There are Nucleo boards for the STM32G4:


The NUCLEO-G474RE board


Full-featured evaluation boards:

Around the Industry

There are many manufacturers in this field, each taking a somewhat different slant, so, as always, the designer has to pick and choose which device offers the most relevant feature for their own application. Here are two examples:

  • Maxim Integrated offers the MAX32651. It includes embedded security and is suitable for low power devices such as industrial sensors, wearables, and portable medical supplies. Its execution speed is comparable to the STM32G4 and it offers what Maxim describes as "the biggest memories in their class and a massively scalable memory architecture."
  • The MSP430F1611 from Texas Instruments is a 16-bit ultra-low-power MCU with 48kB flash, 10240B RAM, a 12-bit ADC, dual DACs, and two USARTs.



Eyeing the STM32G4 series? What applications would you want to try with these MCUs?


Note: This article was updated on June 18th, 2019 to replace the MAX32591 with the MAX32651 for a more apt comparison between MCUs.