Microcontrollers target digital power applications

By Gina Roos, editor-in-chief

STMicroelectronics has developed a new series of STM32 microcontrollers designed for smart devices with more sensor-driven features and higher-efficiency power technologies, such as silicon carbide (SiC) or gallium nitride (GaN). Designed for advanced digital power applications and consumer and industrial appliances, the STM32G4  packs two new mathematical accelerators for increased speed, advanced analog peripherals for more sensors and user features, and enhanced security features. Applications include e-bikes, digital power supplies, advanced motor controls, lighting, and building-automation products.

The new STM32G4 microcontrollers feature two new hardware mathematical accelerators to boost processing of applications using Coordinate Rotation Digital Computer, or CORDIC, a computationally efficient algorithm for handling elementary mathematical functions with high accuracy and filtering functions. These accelerators speed calculations, such as trigonometry for energy-saving motor controls in appliances or air conditioners and filtering for signal conditioning or digital power control, and do it faster and more efficiently than the main processor, said ST. In addition, by offloading the tasks, it enables the core processor to receive more sensor data and control more user functions.

Other features include higher-resolution power conversion timers with a variety of built-in functions that offload the CPU, higher-performing analog peripherals and converters, ultra-speed connections, and support for the latest USB-C interface with Power Delivery that allows for fast charging or powering devices up to 100 W.

For greater protection, the MCUs incorporate scalable securable memory area for secret storage and secure live firmware upgrades, debug-access prevention after programming, AES-256 encryption, unique device ID, and true random-number generator (TRNG).

Key specs include:

• Built-on 170-MHz implementation of the Arm Cortex-M4 core, with floating-point unit and DSP extensions
• A high-resolution timer with 12 independent channels with 184-ps resolution each, self-compensated versus temperature and voltage drift
• Up to 25 advanced analog peripherals, including:
  • Up to five 12-bit 4-Msample/s analog-to-digital converters (ADCs) 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/s digital-to-analog converters (DACs)
  • Up to seven comparators with 16.7-ns propagation delay

• CAN-FD industrial connectivity, offering up to eight times the payload bit rate of standard CAN
• Less than 16 5 µA/MHz in run mode for longer battery life
• Larger on-chip RAM, up to 128 Kbytes with parity bit
• Up to 512-Kbyte flash memory with error code correction (ECC)
• Increased DMA and external-interrupt flexibility

Digital or analog optimization through Access Line, Performance Line, and High-Resolution Line MCU variants

ST plans to introduce 152 devices for this family, of which more than 100 are currently available, ranging from Access Line devices in 32-pin packages to Performance Line and High-Performance Line MCUs with up to 107 fast input/output pins. Prices start from $1.68 in quantities of 10,000 for the STM32G431K6U6  with 32-Kbyte flash memory in the 32-pin QFN32 package.

Nucleo boards (NUCLEO-G474RE  and NUCLEO-G431RB ) and full-featured evaluation boards (STM32G474E-EVAL  and STM32G484E-EVAL  with crypto) are available for the STM32G4 MCUs and the STM32CubeG4  software pack. There are also a dedicated Motor Control Nucleo pack (P-NUCLEO-IHM03 ), software development kits (X-CUBE-MCSDK  v5.4), and the online motor-control tool, ST-MC-SUITE , to help users find resources for their projects. Dedicated discovery kits leveraging the digital-power and motor-control capabilities of the STM32G4 series will be available in the third quarter of 2019.