Renesas Rolls Out Entry-Level MCU With ‘Best-in-Class’ Power Consumption

April 08, 2024 by Jake Hertz

At Embedded World today, Renesas lifted the curtain on a new family of entry-level MCUs filling out its RA series. We spoke to Renesas' Masashi Ueda to learn more.

We kick off our coverage of Embedded World 2024 this week with a new MCU from Renesas. The show runs April 9 - 11 this week in Nuremberg, Germany, and All About Circuits' Editor-in-Chief Jeff Child was on-site in the Renesas booth to learn more about their new product offerings.


Jeff Child learns about new 32-bit MCU and sensor systems from Renesas at Embedded World 2024.

Jeff Child learns about new 32-bit MCU and sensor systems from Renesas' Seraphin Sepa Bikek at Embedded World 2024.


Low power is one of the primary factors in an engineer’s choice of microcontroller (MCU). In an ideal world, an MCU would be performant enough to monitor and control an embedded system while minimizing power consumption to extend the lifetimes of battery-powered systems. Simultaneously achieving both performance and power efficiency is often a contradictory task, however. 

Today, Renesas announced a new family of entry-level MCUs that offers “best-in-class” power consumption figures. All About Circuits interviewed Renesas' product marketing manager of the RA0 series, Masashi Ueda, to hear more about the new family firsthand.



Renesas claims the RA0 provides the lowest overall power consumption for general-purpose, 32-bit microcontrollers.

Renesas Adds the RA0E1 Group MCUs

Renesas designed the RA0E1 Group MCUs for power-sensitive and cost-conscious applications. 

These microcontrollers are built on a 110-nm, low-power process and implement an energy-efficient Arm Cortex-M23 32-bit core. Based on the Armv8-M architecture and clocked at a maximum frequency of 32 MHz, the MCU core helps the devices strike a balance between performance and power consumption. Offering up to 64 KB of code Flash memory and 12 KB of SRAM, the devices provide sufficient space for application code and data storage for embedded applications. 


System block diagram of the RA0E1 group MCUs

System block diagram of the RA0E1 group MCUs. 

A defining feature of the RA0E1 Group MCUs is their exceptional power efficiency. According to Renesas, the family has set a new industry benchmark with a power consumption of only 84.3 μA/MHz in active mode and as low as 0.82 mA in sleep mode.

“It's like a car that gives you amazing mileage—not just on the highways but in idle mode, too,” Ueda remarked.

Additionally, Renesas introduces a Software Standby mode that further reduces power consumption to 0.2 µA, coupled with a fast wake-up capability through its high-speed on-chip oscillator (HOCO), enabling devices to remain in a low-power state longer and respond quickly when action is required.

“It is distinguished not only by its efficient power usage during active states but also by its exceptional standby current performance, particularly during SRAM retention,” Ueda said. “Additionally, it offers quick wake-up from standby mode, making it easier for applications that frequently wake up from sleep mode.”

The RA0E1 MCUs also incorporate various peripherals that contribute to their versatility. These include multiple UARTs, simplified SPIs, an IIC, and a 12-bit ADC. The MCU includes numerous safety features, such as SRAM parity check, illegal memory access detection, true random number generator (TRNG), and Flash read protection. The integrated HOCO maintains its precision across a wide temperature range (-40°C to 105°C), negating the need for external oscillators, simplifying design, and reducing system costs.


An 'Entry-Level' Offering

Renesas is marketing this new MCU as an entry-level device. This classification targets those new to the microcontroller domain or projects that require simplicity and efficiency over advanced capabilities. The device balances cost, ease of use, and essential MCU features to support cost-effective, low-power applications.

Renesas complements the RA0E1's hardware capabilities with its Flexible Software Package (FSP), which accelerates application development by providing infrastructure software components, including RTOS support, peripheral drivers, and connectivity stacks. 


The Renesas Flexible Software Package

The Renesas Flexible Software Package.


“The Flexible Software Package up and down the RA line lets you reuse any kind of IP that you've developed,” Ueda said. “You could develop it for RA0, and then if you need to move it up to RA2, you can do that. Or, if you have something that was developed for an R2, now you can drop it down to an R0.”

Once the design graduates from “entry-level” and a designer needs a more sophisticated MCU, he or she can easily port the design to a different Renesas device.


Now Available With Support

According to Renesas, the RA0E1 group MCUs are best suited for IoT devices, industrial automation and sensors, and home appliances. The devices and the FSP are now available—both of which are supported by the RA0E1 Fast Prototyping Board.

“In 2025, 2026, and beyond, we plan to broaden the R0 series even more with additional devices in the pipeline,” Ueda said. “Our 0 series will continue to be a reliable and innovative choice for the customer's design requirements.



All images used courtesy of Renesas.