Features
- 32MHz Renesas RL78-S3 CPU core
- 512KB flash (dual bank) and 32KB SRAM
- 8KB data flash memory (100,000 program/erase (P/E) cycles)
- 44-pin to 100-pin package lineup with a wide variety of package options including LQFP, LFQFP, and HWQFN
- Built-in LCD controller supporting 19 to 56 segment signal outputs and 4 to 8 common signal outputs
- Capacitive sensing unit supports up to 36ch
- Rich timer functions including 16-bit general purpose timers, 32-bit and 16-bit low-power inverter timers, 16-bit Timer RJ, 16-bit Timer KB, and RTC
- 12-bit A/D converter, 8-bit D/A converter, comparator, and temperature sensor
- SCI (UART, Simple SPI, Simple I2C), SPI, and I2C bus
Description
The Renesas RL78/L23 microcontroller has an RL78-S3 CPU core and rich peripheral features to deliver a better design experience that allows high-level system design while reducing power consumption, system cost, and overall footprint through an extensive range of peripheral functions and low-power operation. RL78/L23 is designed to meet the dynamic requirements of human-machine interface (HMI) applications, featuring capabilities such as capacitive touch sensing and segment LCD control. Additionally, HMI application systems can stay up-to-date, since RL78/L23’s dual-bank flash memory enables continuous firmware updating without interrupting system operation. RL78/L23 also supports rich timer functions including 16-bit general-purpose timers, 32-bit and 16-bit low-power inverter timers, 16-bit Timer RJ, 16-bit Timer KB, and RTC. Timer KB can generate up to 3 channels of PWM signals suitable for controlling power supplies, lighting, and inductive heating (IH) control.
The EEMBC (Embedded Microprocessor Benchmark Consortium) benchmark “ULPMark-PP (ULPMark-Peripheral Profile)” has registered the new score of 215 (1.8V) and 126 (3.0V) as the world's highest score for a 16-bit LCD MCU (as of August 27, 2025). ULPMark-PP is an international benchmark for quantitatively evaluating the energy efficiency of peripheral functions integrated within microcontrollers.
Parameters
| Attributes | Value |
|---|---|
| Program Memory (KB) | 64, 128, 256, 512 |
| Data Flash (KB) | 8 |
| RAM (KB) | 16, 32 |
| Carrier Type | Full Carton (Tray), Full Tray (Tray), Tape & Reel |
| Supply Voltage (V) | 1.6 - 5.5 |
| I/O Ports | 40, 44, 48, 60, 76, 95 |
| Temp. Range (°C) | Ta = -40 to +105 |
| Operating Freq (Max) (MHz) | 32 |
| USB FS (host ch/device ch) | ( 0 / 0 ) |
| SCI or UART (ch) | 5, 6, 7, 8 |
| SPI (ch) | 5, 6, 7, 8 |
| I2C (#) | 8, 9, 10 |
| CAN (ch) | 0 |
| CAN-FD (ch) | 0 |
| Wireless | No |
| LIN (#) | 1 |
| 16-Bit Timer (ch) (#) | 9, 11 |
| 12-Bit A/D Converter (ch) | 8, 9, 10, 13 |
| 10-Bit A/D Converter (ch) | 0 |
| 24-Bit Sigma-Delta A/D Converter (ch) | 0 |
| 12-Bit D/A Converter (ch) | 0 |
| 10-Bit D/A Converter (ch) (#) | 0 |
| 8-Bit D/A Converter (ch) | 2 |
| Capacitive Touch Sensing Unit (ch) | 16, 18, 20, 25, 34, 36 |
| Segment LCD Controller | Yes |
| Security & Encryption | Unique ID, TRNG |
Product Comparison
| RL78/L23 | RL78/L13 | RL78/L12 | RL78/I1C | |
| Operating Freq (Max) (MHz) | 32 | 24 | 24 | 24, 32 |
| Program Memory (KB) | 128, 256, 512 | 16, 32, 48, 64, 96, 128 | 8, 16, 32 | 64, 128, 256, 512 |
| RAM (KB) | 16, 32 | 1, 2, 4, 6, 8 | 1, 1.5 | 6, 8, 16, 32 |
| Data Flash (KB) | 8 | 4 | 2 | 2 |
| Lead Count (#) | 52, 64, 80, 100 | 64, 80 | 32, 44, 48, 52, 64 | 64, 80, 100 |
| Capacitive Touch Sensing Unit (ch) | 20, 25, 34, 36 | 0 | 0 | 0 |
| 16-Bit Timer (ch) (#) | 11 | 9 | 8 | 8, 10 |
| Asynchronous General Purpose Timer / Interval Timer (ch) | 11, 14 | 1 | 1 | 3 |
Application Block Diagrams
 | Smart Touch Panel Smart touch panel with low-power MCU enables real-time air quality, temperature, and touch control. |
 | Air Fryer Toaster Oven with Digital Controls Smart air fryer design supports sensors and uses touch HMI to deliver fast, healthy, perfectly cooked meals. |
 | Toaster Kettle Grill with Digital Controls This system enables faster, precise cooking with intuitive touch controls and display. |
 | Corded Stand Blender with Digital Controls Smart blender system with an intuitive UI and efficient motor control powered by an integrated MCU. |
 | Induction Heating Rice Cooker Smart IH rice cooker with precise temperature control, compact MCU, and energy-efficient design. |
 | LoRaWAN Gas Meter LoRaWAN network enables automatic, efficient gas meter shutdown with low power and long-range benefits. |
 | Power System for Smart Power Meter with 4G Module Smart power meter system ensures always-on operation with efficient energy use. |
Additional Applications
- Home Appliances
- Metering
- Industrial Consumer
- Healthcare
- Building Automation
- Industrial Automation