One of the biggest trends impacting the microcontroller (MCU) market is that everything is getting smarter and connected — homes, buildings, vehicles, and medical devices. All of this intelligence and connectivity means more processing power is needed while achieving low power consumption. Add some artificial intelligence and robust security, it becomes a bigger challenge for chipmakers.
In many, if not most, IoT applications, power consumption and enhanced security are two of the biggest pain points for designers. This has driven many chipmakers to boost their product offerings over the past six months that deliver on both requirements.
Renesas Electronics Corp. is one chipmaker who has developed microcontroller families that keenly address these issues. One of the most recent product introductions is the expansion of its RA4 Series with 12 new RA4M2 Group MCUs. These are a triple threat, delivering very low power consumption, high performance, and enhanced security for industrial and IoT edge applications.
The RA4M2 Group MCUs offer operating frequencies up to 100 MHz, an operating current of 80 µA/MHz in active mode, and low standby current of 0.7 mA, along with a fast wakeup time from standby of 30 µs.
The RA4M2 MCUs use the Arm Cortex-M33 core based on the Armv8-M architecture. They feature Arm TrustZone technology and Renesas’s Secure Crypto Engine. The Secure Crypto Engine incorporates multiple symmetric and asymmetric cryptography accelerators, advanced key management, security life-cycle management, power-analysis resistance, and tamper detection. This combination of features enables safety and security in IoT edge devices for low-power applications.
Other features include integrated flash memory of 512 KB, 384 KB, or 256 KB along with 128-KB SRAM, a capacitive touch sensing unit, advanced analog with one analog-to-digital converter (ADC), and USB 2.0 full-speed. The devices are available in 48-pin to 100-pin LQFP packages as well as 48-pin QFNs.
For ease of development, Renesas offers the Flexible Software Package (FSP) that includes a HAL driver. The FSP uses a GUI to accelerate the development process while making it easy for designers to switch from 8-/16-bit MCU designs. Other resources include a range of tools and access to the Arm partner ecosystem to help speed time to market.
In addition, the RA6M4 MCU Group devices with the FSP have been PSA Level 2–certified, expanding on the PSA Certified Level 1 achieved by the RA4 and RA6 Series MCUs. The RA6M3, RA6M4, and RA4M2 MCU groups have all achieved SESIP1 certification, with Physical and Logical Attacker certifications.
Renesas also added an ultra-low–power MCU with advanced capacitive touch sensing for IoT node human-machine interface (HMI) applications. The 32-bit Arm Cortex-M23–based RA2L1 MCU group offers flexible power modes for lower average power in multiple applications.
(Image: Renesas Electronics)
Renesas expanded the RA2L1 microcontroller family with 20 new devices. The advanced capacitive touch IP in the RA2L1 MCUs provides enhanced operability for a variety of touch and touchless system implementations. The RA2L1’s capacitive touch noise tolerance meets the requirements of IEC EN61000-4-3 Level 4 (radiated) and EN61000-4-6 Level 3 (conducted) to ensure reliable operation with minimal sensing errors.
In terms of power consumption, the RA2L1 MCUs offer an operating current of 64 μA/MHz and software standby current of 250 nA with less than 5-µs fast wakeup. They use the company’s 110-nm low-power process for active and sleep/standby modes and special power-down modes designed for battery-driven applications. This enables users to minimize power consumption close to the standby levels to extend battery life.
The capacitive touch sensing combined with ultra-low power make the RA2L1 MCUs suited for home appliance, industrial and building automation, medical and health-care, and consumer HMI IoT applications. These devices also are available in 48- to 100-pin LQFP packages.
Another power saver is the STMicroelectronics STM32U5 microcontroller with advanced performance and cybersecurity for smart applications, including wearables, personal medical devices, home automation, and industrial sensors. The STM32U5 series combines the energy-efficient Arm Cortex-M33 core with the company’s proprietary power-saving features and on-chip IP to reduce energy demand.
(Image: STMicroelectronics)
ST said the MCUs introduce an autonomous mode that lets direct memory access and peripherals keep working while most of the device sleeps in order to save power. It also offers granular control over operating modes that allows part of the MCU’s memory to be turned off in order to avoid powering unused cells. These STM32U5 MCUs are manufactured using 40-nm process geometry, which saves power in dynamic operating modes as well as power-saving modes.
Other power-saving features include dynamic voltage scaling, which optimizes energy consumption according to the workload, and the ST ART Accelerator to read flash memory efficiently. The STM32U5 MCUs also integrate an advanced DC/DC converter and low-dropout regulator, connected in parallel and selectable on the fly, which can cut dynamic power consumption to less than 19 µA/MHz.
In addition to greater flash density, now with up to 2 MB on-chip, upgraded peripherals include an advanced high-speed 14-bit ADC and error-correction–code memory, along with a multi-function digital filter and audio digital filter that enhance the capabilities of ST’s digital filter for sigma-delta modulator.
These STM32 MCUs also feature advanced cybersecurity with new hardware-based protection targeting PSA and SESIP (Security Evaluation Standard for IoT Platforms) Assurance Level 3. Features include AES encryption and public key authorization that are hardware-resistant to side-channel attacks by differential power analysis, secure data storage with a hardware unique key, active tamper detection, and internal monitoring that can erase secret data in the event of perturbation attacks.
To accelerate development, STMicroelectronics offers the STM32U5 IoT Discovery Kit (B-U585I-IOT02A) that combines the MCU with a Wi-Fi module, Bluetooth module, and various sensors. Microsoft uses this kit as a reference board for the new Azure Certified Device program, which will be available later in the year.
Tackling the tradeoff between performance and cost, the STM32H7 microcontroller family from STMicroelectronics expand the high-performance end of the company’s STM32 family with a range of single-core MCUs that bring high-end features such as rich graphics, AI, and state-of-the-art cyber-protection to cost-sensitive smart and connected devices.
Built on the Arm Cortex-M7 core, the key innovation in the STM32H7 microcontroller family is its ability to operate at 550 MHz, the fastest core speed in the market, among MCUs that integrate flash storage on-chip (up to 1 MB of flash) to run deeply embedded applications, said ST. In addition, the devices can interact with off-chip storage while ensuring full execution performance and security. With features such as flexible memory controller and Octal SPI memory interface, designers can address memory-hungry applications, such as high-resolution, full-color graphics and video that demand a large frame buffer.
Other features include 32-KB I-cache and D-cache sizes; FMAC (filtering) and Cordic (trigonometric) blocks for mathematical acceleration; advanced analog peripherals, including two 16-bit ADCs and one 12-bit ADC in the low-power domain; and support for several industrial connectivity standards.
Security tools for enhanced cyber-protection include the STM32Trust security suite including on-the-fly decryption that allows encrypted code to be executed from external memory and secure firmware install. Out-of-the-box security features include secure boot, symmetric (hardware or software library) encryption, and cryptographic key provisioning. Asymmetric encryption (software library) is also available. Cryptographic processing is handled with a true random-number generator; hardware acceleration for AES-128, AES-192, and AES-256 encryption; and support for GCM and CCM2, Triple DES, and hash (MD5, SHA-1 and SHA-2) algorithms.
The STM32H7 MCUs are supported in the STM32Cube ecosystem, which is comprised of tools, embedded software, and middleware including graphics libraries, communication stacks, and application-code examples such as motor control, AI, and advanced security. Development resources include the STM32H735G-DK Discovery Kit and NUCLEO-H723ZG Nucleo-144 board for building prototypes and proof-of-concept models.
In addition to meeting new power efficiency and security requirements, designers also face a variety of design complexity issues. One of Microchip Technology Inc.’s latest MCUs tackles analog system design challenges in mixed-signal IoT systems. These MCUs integrate configurable analog and digital peripherals and are available in a range of memory sizes, packages, and price points.
Addressing the challenge of sensor-based IoT systems that combine analog functionality and digital control capability, Microchip has introduced the first PIC and AVR MCUs that combine advanced analog peripherals and multi-voltage operation with inter-peripheral connections.
Delivering both increased system integration and reduced signal-acquisition times, the PIC18-Q41 and AVR DB microcontroller families enable designers to use the MCUs “as a single-chip controller or as an intelligent analog signal-conditioning component in a larger system,” said Microchip.
For signal conditioning in space-constrained sensing and measuring applications such as IoT end nodes and industrial, medical devices, wearables, automotive, and lighting systems, the PIC18-Q41 MCU provides a configurable operational amplifier (op amp), ADC with computation, and DACs. The PIC18-Q41 is available in compact 14- and 20-pin packages and is a companion to Microchip’s 32-bit MCUs and other controllers that require analog integration. It is particularly well suited for IoT and large-scale AI at the edge, including predictive-maintenance edge nodes in a smart factory.
(Image: Microchip Technology)
The addition of three independent and highly configurable op amps, a 12-bit differential ADC, a 10-bit DAC, three zero-cross detectors, and core independent peripherals (CIPs) makes the AVR DB MCU suited for virtually any application involving analog signal-conditioning and processing functions, said Microchip.
The new products are supported by Microchip’s MPLAB X integrated development environment, MPLAB Code Configurator (MCC), and the MPLAB Mindi Analog Simulator. MCC is a free software plug-in that provides a graphical interface to configure peripherals and functions specific to an application. The AVR DB also is supported by Atmel START, Atmel Studio, and third-party tools such as IAR and the GCC C compiler.
Both microcontroller families offer a development board with programming and debugging capabilities: the PIC18F16Q41 Curiosity Nano Evaluation Kit (EV26Q64A) and the AVR DB Curiosity Nano Evaluation Kit (EV35L43A). Quick start guides for the PIC MCU and the AVR MCU are available to start projects immediately.
Microchip also addresses the challenges of designing smart medical devices with complex control systems with its new PIC18-Q40 microcontroller, featuring a variety of CIPs. These CIPs help reduce the requirements of external components, which decrease total system costs. The MCU can be used in a wide range of embedded applications, including remote medical care, wearables, consumer, automotive, industrial, and IoT.
The PIC18-Q40 MCU family extends Microchip’s PIC18 portfolio to low pin count with large flash memory, small footprint packages, and analog and digital CIPs for portable and space-constrained designs. Microchip offers more than 20 CIPs to autonomously handle common embedded tasks, such as timers, simplified pulse-width modulation (PWM) output, configurable logic cells, ADC with computation, and multiple serial communications.
“CIPs offer flexible, easy-to-use building blocks for developers to create a customized device,” said Stephanie Pinteric, 8-bit Microcontroller Business Unit, Microchip Technology. “It brings to designers the advanced functional capabilities of CIPs that handle a smart medical device’s critical tasks with no code or supervision from the CPU to maintain operation. This greatly simplifies the implementation of complex smart device control systems while creating new opportunities for designers to innovate.”
They also allow smaller, lower-power PIC MCUs to perform timing-critical and core-intensive system tasks in hardware with no code or supervision from the CPU to maintain operation, she said. “While the CPU is free to do other tasks or go to sleep to save power, the CIPs provide the total system with precision control, fast response, power saving, and lower system costs.”
The MCUs feature intelligent peripherals that can automate signal-analysis functions and provide programmable logic, enabling designers to tailor such things as waveform generation, timing measurements, and more, she said. They also provide compensation information to digital PWMs and provide auto-shutdown capability without CPU intervention.
Microchip offers development tools that allow designers to customize combinations of CIPs and generate application code.
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