The RA0 family from Renesas, known for its low-cost and low-power Cortex-M23 microcontrollers, has just expanded with the introduction of the new RA0L1. This device not only continues the series’ focus on affordability and efficiency but also becomes the first in the family to feature integrated capacitive touch sensing. It targets designers of battery-powered devices that require fast and reliable touch response, low current draw, and extended operating life.
Core Features
The RA0L1 MCU integrates up to 64KB flash and 16KB SRAM, operating across a wide voltage range of 1.6V to 5.5V, making it suitable for a variety of power supply environments. Peripherals are abundant, including a 12-bit ADC, on-chip temperature sensor, multiple UART/I²C/SPI interfaces, timers, RTC, and a true random number generator.
Renesas’ proprietary self-capacitance technology enables support for up to 24 capacitive touch channels, while a ±1% high-accuracy on-chip oscillator ensures precise timing. On the security side, the device incorporates a true RNG (TRNG) and a unique 128-bit device identifier for authentication and system integrity.
RA0L1 MCU – Key Specifications
| Category | Details |
|---|---|
| Core | Arm Cortex-M23 CPU, Armv8-M instruction set, up to 32MHz |
| Memory |
- 16KB SRAM with parity check - Up to 64KB Code Flash - 1KB Data Flash with 1M erase/write cycles - Flash Read Protection (FRP) - 128-bit Unique ID for device authentication |
| Human-Machine Interface (HMI) |
- Up to 24 capacitive touch channels - 8 Current-Controlled Driver (CCD) ports for optimized touch signal drive |
| Serial Interfaces |
SAU: 5x simplified SPI, 6x simplified I²C, 2x UART, 1x LIN-compatible UART UARTA: 2x enhanced UART IICA: 2x I²C bus interfaces |
| GPIO | Up to 44 I/Os (package-dependent), 5V tolerant, open-drain support, pull-up options |
| Analog |
- 12-bit ADC with up to 13 channels - Integrated temperature sensor and reference voltage |
| Timers |
- 16-bit TAU: 8 channels - 32-bit interval timer (2x16-bit or 4x8-bit) - RTC with calendar, alarm, 1Hz output - Up to 7 PWM outputs |
| Clock System |
- Main Oscillator: 1–20MHz external crystal - Sub Oscillator: 32.768kHz - HOCO: 24/32MHz - MOCO: 4MHz - LOCO: 32.768kHz - Clock calibration and output support |
| Safety |
- SRAM parity check - Invalid memory access detection - Frequency monitoring - ADC self-test - Output level monitoring - CRC calculator - Register write protection |
| Security |
- 128-bit Unique ID - True RNG (TRNG) - Flash access windowing - Flash read-out protection |
| Other Features |
- Data Transfer Controller (DTC) - Event Link Controller (ELC) - Power-on Reset - Low-Voltage Detection - Multiple low-power modes - RTC operation in standby |
| Power |
- Voltage: 1.6–5.5V - Active: ~2.9mA - Sleep: ~0.92mA - Software standby: 0.25µA |
| Temperature Range | -40°C to +105°C or -40°C to +125°C (depending on model) |
| Packages |
- 48-pin LFQFP (7×7mm, 0.5mm pitch) - 48-pin HWQFN (7×7mm, 0.5mm pitch) - 32-pin LQFP (7×7mm, 0.8mm pitch) - 32-pin HWQFN (5×5mm, 0.5mm pitch) - 24-pin HWQFN (4×4mm, 0.5mm pitch) - 20-pin LSSOP (4.4×6.5mm, 0.65mm pitch) |
Key Advantages and Development Ecosystem
One of the biggest strengths of the RA0L1 is its ultra-low power consumption. With active current at ~2.9mA and standby down to 0.25µA, battery-powered devices can run significantly longer—Renesas claims up to 90% current reduction compared with older solutions.
For developers, Renesas provides full software support through the Flexible Software Package (FSP), which includes CMSIS-compliant drivers, HAL, RTOS integration, and middleware for touch sensing, communications, and security.
The RA0L1 is supported in e² studio IDE, compatible with GCC, IAR, and Arm Keil MDK toolchains. Touch features can be configured and debugged with the QE for Capacitive Touch tool, while FreeRTOS and other mainstream embedded OS options are also supported.
Renesas FPB-RA0L1 Fast Prototyping Board
Renesas RSSK-RA0L1 Capacitive Touch Evaluation Board
Evaluation Boards
To accelerate prototyping, Renesas has released several boards:
- FP-BRA0L1 Evaluation Board
- FPB-RA0L1 Quick Prototyping Board
- RTK0EG0065S01001BJ Evaluation Kit
- RSSK-RA0L1 Capacitive Touch Starter Kit
The FPB-RA0L1 includes a 48-pin RA0L1 MCU (R7FA0L1074CFL), onboard SEGGER J-Link debugger, Arduino Uno and Pmod interfaces, plus two capacitive touch buttons for HMI testing. Its compact 56mm × 93mm form factor makes it practical for quick bring-up.
The RSSK-RA0L1 is tailored for touch development, bundling a J-Link and dedicated QE touch software with GUI support. Engineers can tune sensitivity, auto-generate code, and prototype buttons, sliders, and wheels—shortening time-to-market for capacitive touch products.
Product Variants and Pricing
According to Renesas, the RA0L1 family includes 68 device options:
- High-end variant: R7FA0L1073CFL (64KB flash, 16KB SRAM, 48-pin). Digi-Key lists it at $2.30 (1 unit) or $1.16 (5,000 units).
- Entry variant: R7FA0E1073CSC (32KB flash, 16KB SRAM, 20-pin). Optimized for cost-sensitive and compact designs. Pricing TBD.
The FPB-RA0L1 Quick Prototyping Board is already available at distributors like Mouser for $15.34.
For full documentation and selection guides, engineers can refer to the official Renesas RA family product pages.
