ST launches next gen power-saving microcontrollers -

ST launches next gen power-saving microcontrollers


STMicroelectronics has announced a new generation of power-saving microcontrollers (MCUs), the STM32U5 series, which are designed for stringent power/performance requirements in smart applications such as wearables, personal medical devices, home automation and industrial sensors.

The new MCUs are manufactured using 40nm process geometry, which saves power in dynamic operating modes and power-saving modes. The new STM32U5 series combines the Arm Cortex-M33 core, the ability to use Arm Keil MDK for maximum power optimization, and new features such as advanced security with new hardware-based protection targeted at PSA Warranty Level 3 and SESIP (security evaluation standard for IoT platforms), as well as graphics accelerators to enhance the user experience.

IoT for the future

In the growing internet of things (IoT) era, in order for things to connect to the network, they need to be smart – that is, equipped with intelligence. This means they need a microcontroller and software that manages the interfaces, on one side towards the real world, i.e. the sensors, and on the other side towards the internet through the communication node.

Power consumption in active mode is surely the fundamental parameter, but it is not enough. The object could be inactive for long periods; in this case it is convenient to put the system in a stand-by state, and then becomes its fundamental consumption. The two extremes of power consumption are active mode, during which the microcontroller operates at full power, and shutdown, during which no operation is performed. In between, there may be other modes that involve operations with reduced performance in order to lower power consumption. There are also other mechanisms that the device can be equipped with that lead to a reduction in the overall consumption of the system in which the microcontroller is used.

Low power and security

In the last five years, ST has increased its share of microcontrollers, in particular the STM32 series with shallow power. The evolution with the new series presented at this year’s embedded world aims to offer high power performance as well as superior performance and security over the latest versions. An advanced DC/DC converter and LDO regulator enable the STM32U5 MCUs to reduce dynamic power consumption to less than 19µA/MHz.

The new MCU includes the Arm TrustZone technology from the previous STM32L5 and a set of specific security features such as:

  • AES encryption and public key authorization (PKA) are now hardware-resistant against side-channel attacks using differential power Analysis (DPA)
  • Secure data storage with a unique hardware key (HUK)
  • Active tamper detection
  • Internal monitoring that can erase secret data in the event of a disruptive attack, a feature that meets PCI Security Standards Council (PCI SSC) requirements for point of sales (POS) applications.
ST MCU figure1 block diagram
Figure 1: Block diagram of STM32U5

For this microcontroller, ST created the STM32U5 IoT discovery kit (B-U585I-IOT02A), which combines the MCU with a Wi-Fi module, a Bluetooth module and various sensors. ST said Microsoft chose this kit as the reference board for its new Azure Certified Device program. 

ST MCU figure 2
Figure 2: Discovery kit for IoT node with STM32U5 Series

An advanced next-generation 14-bit high-speed analog-to-digital converter (ADC) is integrated and ready for sensing and tracking applications.

ST MCU figure 3
Figure 3: Circuit application of STM32U5

A multi-function digital filter (MDF) and a digital audio filter (ADF) enhance the capabilities of ST’s high-performance sigma-delta modulator digital filter (DFSDM). With enhanced audio performance, it is now possible to use low-cost, low-power microcontroller-based use case AI systems. In addition, with error correction code (ECC) memory as part of the device RAM, STM32U5 MCUs can also satisfy safety-centric applications.

The STM32U5 MCUs are currently in the sampling phase while volume production will begin in September 2021. Pricing starts at $3.60 USD. A wide choice of packages will be available including a 4.2 mm x 3.95 mm WLCSP and 7 mm x 7 mm UQFN48 and UFBGA169.

Related Contents:

For more Embedded, subscribe to Embedded’s weekly email newsletter.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.