Ultra-low-power RL78/L23 MCUs with segment LCD displays & capacitive touch for HMI applications
Renesas Electronics Corporation, a premier supplier of advanced semiconductor solutions, 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 32MHzBuilt-in segment LCD controller and capacitive touchUp to 512KB of dual-bank flash memory for seamless FOTAUp to 32KB of SRAM and 8KB of data flashSMS for ultra-low power operationIH Timer (KB40) supporting up to 3-channel induction heating controlWide operating voltage range from 1.6V to 5.5VOperating temperature range of -40°C to +105°CMultiple serial interfaces including UART, I2C, CSIIEC60730-compliant self-test library44-100-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.
