Renesas Introduces Ultra-Low-Power RL78/L23 MCUs for Next-Generation Smart Home Appliances

　　Renesas Electronics Corporation (TSE:6723), a premier supplier of advanced semiconductor solutions, today introduced the new 16-bit RL78/L23 microcontroller (MCU) group, expanding its low-power RL78 family. Running at 32MHz, the RL78/L23 MCUs combine industry-leading low-power performance with essential features such as dual-bank flash memory, segment LCD control, and capacitive touch functionality to support smart home appliances, consumer electronics, IoT and metering systems. These compact, cost-effective devices address the performance and power requirements of modern display-based human-machine interface (HMI) applications.

　　Ultra-Low Power Operation with Optimized LCD Performance

　　The RL78/L23 is optimized for ultra-low power consumption and ideal for battery-powered applications that spend the majority of time in standby. They offer an active current of just 109μA/MHz and a standby current as low as 0.365μA, along with a fast 1μs wake-up time to help minimize CPU activity. The LCD controller’s new reference mode, VL4, reduces LCD operating current by approximately 30 percent when compared to the existing RL78/L1X group. The MCUs come with SMS (SNOOZE Mode Sequencer), which enables dynamic LCD segment display without CPU intervention. By offloading tasks to the SMS, the devices minimize CPU wake-ups and contribute to system-level power savings. These innovations significantly extend battery life, simplify design and reduce replacement costs, while minimizing environmental impact.

　　The RL78/L23 offers a wide operating voltage range of 1.6V to 5.5V, which supports direct operation from 5V power supplies commonly used in home appliances and industrial systems. This capability reduces the need for external voltage regulators. The MCUs also integrate key components such as capacitive touch sensing, a temperature sensor, and internal oscillator, reducing BOM cost and PCB size.

　　Feature-Rich Peripherals for HMI Systems

　　Designed to meet the dynamic requirements of the HMI market, RL78/L23 integrates a suite of advanced features in a compact, cost-effective package. Its built-in segment LCD controller and capacitive touch realize sleek, responsive user interfaces for products such as induction cooktops and HVAC systems. The IH timer (Timer KB40) enables precise multi-channel heat control, which is essential in smart kitchen appliances such as rice cookers and IH cooktops. The devices include dual-bank flash memory for seamless firmware updates via FOTA (Firmware Over-the-Air), allowing continuous system operation in applications like metering, where downtime must be minimized. The dual-bank architecture allows one memory bank to run the user program, while the other receives updates. This approach keeps the system functional throughout the process for improved reliability.

　　“The Renesas RL78 Family of 16-bit microcontrollers has been one of the most successful products since its launch more than 10 years ago, particularly in home appliances,” said Daryl Khoo, Vice President of Embedded Processing at Renesas. “I’m pleased to announce the RL78/L23, a new generation of RL78 microcontrollers with rich features, ideally suited for smart home appliances and cost-sensitive IoT solutions. With these devices, we aim to provide a better user experience with our intuitive development environment so that customers can get to production faster with confidence, based on market-proven Renesas technologies.”

　　Key Features of the RL78/L23

　　16-bit RL78 microcontroller running at 32MHz

　　Built-in segment LCD controller and capacitive touch

　　Up to 512KB of dual-bank flash memory for seamless FOTA

　　Up to 32KB of SRAM and 8KB of data flash

　　SMS for ultra-low power operation

　　IH Timer (KB40) supporting up to 3-channel induction heating control

　　Wide operating voltage range from 1.6V to 5.5V

　　Operating temperature range of -40°C to +105°C

　　Multiple serial interfaces including UART, I2C, CSI

　　IEC60730-compliant self-test library

　　44-100-pin LFQFP, LQFP and HWQFN packages

　　Intuitive Development Environment for Faster Time-to-Market

　　The RL78/L23 comes with an easy-to-use development environment. Developers can leverage robust support tools such as Smart Configurator and QE for Capacitive Touch to streamline system design. Renesas offers the RL78/L23 Fast Prototyping Board which is compatible with Arduino IDE, and a capacitive touch evaluation system for in-depth testing and validation.

　　Winning Combinations

　　Renesas offers Induction Heating Rice Cooker Solution which combines the new RL78/L23 devices with numerous compatible devices from its portfolio to offer a wide array of Winning Combinations. Winning Combinations are technically vetted system architectures from mutually compatible devices that work together seamlessly to bring an optimized, low-risk design for faster time to market. Renesas offers more than 400 Winning Combinations with a wide range of products from the Renesas portfolio to enable customers to speed up the design process and bring their products to market more quickly. They can be found at renesas.com/win.

　　Availability

　　The RL78/L23 MCUs are available today, along with the Fast Prototyping Board (FPB-RL78L23) and the capacitive touch evaluation system (RSSK-RL78L23).