TOKYO, Japan, Aug 28, 2025 – Renesas introduced the RL78/L23, a 16-bit microcontroller (MCU) built for low power and simple interfaces. It runs up to 32 MHz and slots into the RL78 family teams already use. It has features such as flash memory, segment LCD control, and touch functionality to support home appliances, consumer electronics, IoT and metering systems.
Ultra-Low Power Operation with Optimized LCD Performance
Renesas built the RL78/L23 for low power consumption, best-suited for battery devices that are on standby. The MCU draws current of 109μA/MHz and a standby current of 0.365μA, then wakes in 1μs wake-up time to keep CPU activity short. The LCD controller’s VL4 reference mode reduces display current by about 30% compared with the RL78/L1X group. A SNOOZE mode sequencer (SMS) drives LCD segments without CPU intervention, which reduces wake-ups and saves system power. Together, these features extend battery life, simplify design, lower replacement costs, and reduce battery waste. It suits meters, sensors, and small appliances that need a simple display and long runtimes on a battery.
The RL78/L23 operates from 1.6V to 5.5V, supporting 5V power supplies in home appliances and industrial systems. It integrates touch sensing, a temperature sensor, and an internal oscillator, helping reduce BOM cost and PCB size.
Feature-Rich Peripherals for HMI Systems
The RL78/L23 integrates multiple functions into a cost-conscious MCU. Its LCD controller and capacitive touch support responsive interfaces in products like induction cooktops and HVAC controls. The IH timer (Timer KB40) provides multi-channel heating control for kitchen appliances like rice cookers. Dual-bank flash enables firmware updates via FOTA (Firmware Over-the-Air) without stopping the system. One bank runs the application while the other receives the update, which helps metering and similar applications stay online and improves reliability during maintenance.
“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
- Core and performance: 16-bit RL78 at up to 32 MHz, SMS for low-power operation.
- Memory and updates: Up to 512 KB dual-bank flash (FOTA), 32 KB SRAM, 8 KB data flash.
- UI features: Built-in segment LCD controller.
- Control and I/O: IH Timer (KB40) for up to 3-channel induction heating; UART, I2C, CSI.
- Robust design: Voltage range from 1.6V to 5.5V, temperature range of -40°C to +105°C, IEC 60730 self-test library, multiple serial interfaces including UART, I2C, 44–100 pin LFQFP/LQFP/HWQFN packages.
Intuitive Development Environment for Faster Time-to-Market
Developers can leverage 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 testing and validation.
Availability
The RL78/L23 MCUs are available along with the Fast Prototyping Board (FPB-RL78L23) and the capacitive touch evaluation system (RSSK-RL78L23).
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Source: Renesas Electronics
About Renesas Electronics
Renesas Electronics Corp., based in Tokyo, supplies power management integrated circuits (PMICs) and ships more than 1.5 billion power devices annually for computing, industrial, IoT, data center, and communications markets. Its portfolio includes PMICs, discrete devices, GaN power products, and design tools such as PowerCompass and PowerNavigator. These work with microcontrollers, SoCs, and connectivity solutions to support system design. The company was formed in 2010 through the merger of Renesas Technology and NEC Electronics, with origins in semiconductor units of Hitachi, Mitsubishi, and NEC. For the fiscal year ending Dec. 31, 2024, Renesas reported revenue between $9B and $10B.