Renesas launches entry-level low-power MCU RA0

At Embedded World Expo today, Renesas Electronics announced a new entry-level MCU family in the RA Series. All About Circuits spoke with Masashi Ueda of Renesas Electronics to learn more.

Power consumption is one of the main factors engineers consider when selecting a microcontroller (MCU). Ideally, an MCU should provide enough performance to monitor and control an embedded system while minimizing power consumption to extend the life of a battery-powered system. However, achieving both performance and power efficiency is often a conflicting task.

Today, Renesas Electronics launched a new entry-level MCU series that delivers “best in class” power consumption figures. All About Circuits spoke with Masashi Ueda, Product Marketing Manager for the RA0 Series at Renesas Electronics, to get a first-hand look at the new series.

Launched RA0E1 series MCU

Renesas designed the RA0E1 Group of MCUs for applications where both power consumption and cost are sensitive.

These microcontrollers are built with a 110 nm low-power process and feature an energy-efficient Arm Cortex-M23 32-bit core. The MCU core is based on the Armv8-M architecture and runs at up to 32MHz, helping devices strike a balance between performance and power consumption. The device offers up to 64 KB flash and 12 KB SRAM, providing ample space for application code and data storage for embedded applications.

System block diagram of the RA0E1 MCU.

A hallmark of the RA0E1 Series of MCUs is their exceptional power efficiency, which sets a new industry benchmark with power consumption of just 84.3 μA/MHz in active mode and as low as 0.82 mA in sleep mode, according to Renesas.

“It’s like a car that gives you amazing mileage — not only on the highway but also in idle mode,” Masashi said.

In addition, Renesas has introduced a software standby mode that further reduces power consumption to 0.2 µA and provides a fast wake-up function through its high-speed on-chip oscillator (HOCO), allowing the device to remain in a low-power state longer and respond quickly when action is required.

“It is characterized not only by its efficient power usage in its active state, but also by its excellent standby current performance, especially during SRAM retention,” said Masashi. “In addition, it can wake up quickly from standby mode, making it easier for applications that frequently wake up from sleep mode.”

The RA0E1 MCU also integrates a variety of peripherals, which enhances its versatility. These include multiple UARTs, SPI, I2C, and a 12-bit ADC. The MCU includes numerous security features such as SRAM parity, illegal memory access detection, true random number generator (TRNG), and flash read protection. The integrated HOCO maintains accuracy over a wide temperature range (-40°C to 105°C) and eliminates the need for an external oscillator, simplifying design and reducing system cost.

"Entry-level" products

Renesas Electronics targets this new MCU as an entry-level product for those new to the microcontroller world or for projects that require simplicity and efficiency rather than advanced features. The device balances cost, ease of use, and basic MCU features to support cost-effective, low-power applications.

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

Renesas FSP

“The RA Series FSP lets you reuse any type of IP that you develop,” said Masashi. “You can develop it for RA0, and then if you need to upgrade it to RA2, you can do that. Or if you have something that you developed for R2, now you can downgrade it to R0.”

These products can be easily migrated once the design moves from "entry level" to more complex MCUs.

Available Now

Renesas said the RA0E1 Series MCUs are best suited for IoT devices, industrial automation and sensors, and home appliances. The devices and FSPs are available now.

“We plan to further expand the R0 Series with additional devices in 2025, 2026 and beyond,” said Masashi. “Our R0 Series will continue to be a reliable and innovative choice for our customers’ design requirements.”