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.
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 |
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) | - |
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 |
Package Options
Pkg. Type | Pkg. Dimensions (mm) | Lead Count (#) | Pitch (mm) |
---|---|---|---|
LFQFP | 7 x 7 x 1.7 | 48 | 0.5 |
LFQFP | 10 x 10 x 1.7 | 64 | 0.5 |
LFQFP | 12 x 12 x 1.7 | 80 | 0.5 |
LFQFP | 14 x 14 x 1.7 | 100 | 0.5 |
LQFP | 10 x 10 x 1.6 | 44 | 0.8 |
LQFP | 10 x 10 x 1.7 | 52 | 0.65 |
LQFP | 12 x 12 x 1.7 | 64 | 0.65 |
LQFP | 14 x 14 x 1.7 | 80 | 0.65 |
LQFP | 14 x 20 x 1.6 | 100 | 0.65 |
QFN | 7 x 7 x 0.8 | 48 | 0.5 |
Application Block Diagrams
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Smart Touch Panel
Smart touch panel with low-power MCU enables real-time air quality, temperature, and touch control.
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Air Fryer Toaster Oven with Digital Controls
Smart air fryer design supports sensors and uses touch HMI to deliver fast, healthy, perfectly cooked meals.
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Toaster Kettle Grill with Digital Controls
This system enables faster, precise cooking with intuitive touch controls and display.
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Corded Stand Blender with Digital Controls
Smart blender system with an intuitive UI and efficient motor control powered by an integrated MCU.
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Induction Heating Rice Cooker
Smart IH rice cooker with precise temperature control, compact MCU, and energy-efficient design.
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LoRaWAN Gas Meter
LoRaWAN network enables automatic, efficient gas meter shutdown with low power and long-range benefits.
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Power System for Smart Power Meter with 4G Module
Smart power meter system ensures always-on operation with efficient energy use.
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Additional Applications
- Home Appliances
- Metering
- Industrial Consumer
- Healthcare
- Building Automation
- Industrial Automation
Applied Filters:
Filters
Software & Tools
Sample Code
Simulation Models
The RL78/L23 MCU combines ultra-low power operation with rich peripheral features, enabling high-level system design for consumer and industrial HMI applications. It supports capacitive touch sensing, segment LCD control, and advanced timer functions while minimizing system cost and footprint. With dual-bank flash memory, RL78/L23 allows seamless firmware updates without interrupting system operation.
Related Resources
Smart Configurator is a GUI-based tool that can generate code for drivers and middleware and configure pins easily. This video introduces the Smart Configurator for the RL78 Family.
00:00 Opening
00:45 Support Project Template
00:53 Support board usage
01:00 Download software
01:06 Visualize configuration
01:24 Graphical configuration
01:31 Check conflicts
01:31 Generate source codes
01:50 Developer Assistance
This video demonstrates how to import sketches using the RL78 Arduino library into e² studio, as well as how to build and debug them. By debugging in e² studio, you can obtain detailed information and verify the internal workings of the library, which is not possible with the Arduino IDE.
Related Resources
This video introduces how to do AI coding using ChatGPT and the RL78 Arduino-compatible board, including practical examples such as lighting up a 7Seg LED, rotating a motor, and sensing with a temperature and humidity sensor. Even beginners can easily experience AI coding!
Detailed step-by-step instructions:
AI Coding with Chat-GPT for RL78 Microcontroller (Arduino) | Renesas
Related products: RL78/G23-64p FPB
Related sources: Quick Start Guide page (GitHub)
Disclaimer:
1. Informational Purposes Only: This video serves as a general guide to using ChatGPT/GPT-4 to write code for an Arduino RL78 evaluation board. Renesas does not guarantee the accuracy or completeness of the content provided.
ï¼’. Third-Party Rights Infringement: Note that code generated using ChatGPT/GPT-4 might potentially infringe third-party intellectual property rights. Renesas makes no representations or warranties that the use of ChatGPT/GPT-4 will not violate any third-party rights. Users are urged to exercise due diligence to ensure compliance with applicable laws and third-party rights.
3. No Liability: In no event shall Renesas be liable for any damages, data loss, or other adverse consequences that may occur as a result of using the information, code, techniques, or tools demonstrated in this video. You may want to apply industry standard static and dynamic code assessments as AI code has been recognized to possibly contain malware fragments as well as deriving other unwanted outcomes.
This video introduces how to run a sketch on the RL78/G23-64p Fast Prototyping Board using the Arduino IDE 2.
Related resources: Quick Start Guide page (GitHub)
00:00 Opening
00:43 Install the Arduino IDE
01:12 Install the tools
01:35 Write the sketch
01:56 COM port setting
02:24 Board setting
02:41 Compile, upload, LED blinking
This video introduces RL78 LoRa®-based Solution.
It realizes a true low-power wireless IoT system by combination of the world's top-class low power RL78 microcontroller and LoRaWAN®
This video will show you how to set up the RL78 LoRaWAN® Sensor Demo.
Using the RL78 / G23 and LoRaWAN® ecosystem, you can realize both the "LoRaWAN sensor network evaluation" and "IoT system construction using LoRaWAN" with minimal man-hours.
This video will show the steps to connect and operate the RL78 Modbus evaluation environment for master and slave with sample software in the application note.
The evaluation environment uses Renesas' RL78/G22 Fast Prototyping Board and RS-485 Transceivers Evaluation Board.
RL78/G22 Modbus ASCII/RTU Application Note Rev.1.10 (ZIP | English, 日本語)
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Aug 27, 2025
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Aug 27, 2025
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