These compact and cost-effective devices meet the performance and power requirements of modern screen-based human-machine interface (HMI) applications.
The RL78/L23 is optimized for ultra-low power consumption and is ideal for battery-powered applications that spend most of their time in standby mode. It offers an active current of only 109 μA/MHz and a standby current of just 0.365 μA, along with a fast wake-up time of 1 μs to help minimize CPU activity. The new LCD controller reference mode, VL4, reduces LCD operating current by approximately 30% 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 also minimizing environmental impact.
The RL78/L23 offers a wide operating voltage range of 1.6V to 5.5V, enabling direct operation from 5V power supplies commonly used in household appliances and industrial systems. This capability reduces the need for external voltage regulators. The MCUs also integrate key components such as capacitive touch sensors, a temperature sensor, and an internal oscillator, reducing the bill of materials cost and the size of the printed circuit board.
The RL78/L23 integrates a suite of advanced features into a compact and cost-effective package. Its integrated segmented LCD controller and capacitive touch sensor enable the creation of elegant and responsive user interfaces for products such as induction cooktops and climate control systems. The IH timer (Timer KB40) allows for precise heat control across multiple channels, which is essential in smart kitchen appliances such as rice cookers and induction cooktops. The devices include dual-bank flash memory for seamless firmware updates via FOTA (Firmware Over-the-Air), enabling continuous system operation in applications such as 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 operational throughout the process, enhancing reliability.
Key Features of the RL78/L23:
16-bit RL78 microcontroller running at 32 MHz;
Integrated segmented LCD and capacitive touch controller;
Up to 512 KB of dual-bank flash memory for non-interruptible FOTA updates;
Up to 32 KB of SRAM and 8 KB of
SMS data flash memory for ultra-low power operation;
IH timer (KB40) supporting up to 3 channels of induction heating control; Wide operating voltage range of 1.6 V to 5.5 V;
Operating temperature range of -40 °C to +105 °C;
Multiple serial interfaces, including UART, I2C, and CSI;
Self-test library compliant with IEC60730;
44-100 pin LFQFP, LQFP, and HWQFN packages;
Intuitive development environment for faster time to market.
The RL78/L23 includes an easy-to-use development environment. Developers can leverage robust support tools, such as Smart Configurator and QE for Capacitive Touch, to optimize system design. Renesas offers the RL78/L23 rapid prototyping board, compatible with the Arduino IDE, and a capacitive touch evaluation system for in-depth testing and validation.
