Renesas R5F103A8ASP#30

Overview

R5F103A8ASP#30 from Renesas Electronics is a 30-pin LSSOP ultra-low-power 16-bit RL78/G12 microcontroller designed for cost-sensitive consumer applications. It features 4 KB code flash, 512 B RAM, 8-channel 10-bit A/D converter, 1-channel UART, and operates from 1.8 V to 5.5 V at –40°C to +85°C - enabling use in battery-powered remote controls and smart home sensors.

For engineers reviewing the R5F103A8ASP#30 datasheet, R5F103A8ASP#30 pinout, R5F103A8ASP#30 application, or R5F103A8ASP#30 equivalent, key selection criteria include its absence of data flash memory, single UART channel, lack of DMA and safety functions (CRC/SFR guard), and ±5.0% high-speed on-chip oscillator accuracy over industrial temperature range - critical for timing-critical but non-safety-certified embedded control.

Technical Context

The R5F103A8ASP#30 implements the RL78 CPU core with CISC architecture and 3-stage pipeline, delivering 31 DMIPS at 24 MHz. Its peripheral set is trimmed versus R5F102 variants: no data flash, no DMA controller, no simplified I²C (IIC01), and only one UART channel instead of three - reflecting its role as a streamlined, cost-optimized variant for basic serial communication and analog sensing.

It uses a dedicated low-speed on-chip oscillator (15 kHz) for watchdog timer operation and supports main system clock via external crystal (X1/X2, up to 20 MHz) or internal high-speed oscillator (1–24 MHz). Pin multiplexing is managed through the Peripheral I/O Redirection Register (PIOR), enabling flexible signal routing without hardware changes.

Key Specifications

Pinout & Package

Package: 30-pin plastic LSSOP (7.62 mm, 0.65-mm pitch), RoHS-compliant, surface-mountable with standard reflow profile.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with R5F103A8ASP#30, R5F102AAASP#30 adds safety and data retention capabilities at the expense of cost and power, while R5F103AAASP#30 offers headroom for firmware growth without altering hardware design or peripheral constraints.

Availability

R5F103A8ASP#30 is available at Aetrix Electronics and suitable for remote controls, smart thermostat sensor nodes, and small-appliance control panels requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for R5F103A8ASP#30 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, and power management ICs for automotive, industrial, and consumer markets.

The RL78/G12 product line delivers ultra-low-power 16-bit MCUs optimized for cost-sensitive, battery-operated consumer electronics - emphasizing minimal BOM count, integrated peripherals, and energy-efficient operation down to sub-μA sleep currents.

FAQ

What is the maximum operating frequency of the R5F103A8ASP#30?

The R5F103A8ASP#30 supports a maximum high-speed on-chip oscillator frequency of 24 MHz and an external crystal input up to 20 MHz. At 24 MHz, it delivers 31 DMIPS performance. The actual usable frequency depends on VDD: 24 MHz requires VDD ≥ 2.7 V; at 1.8–2.4 V, max is 16 MHz. All timing specifications in the datasheet assume these validated conditions.

Does the R5F103A8ASP#30 include data flash memory?

No, the R5F103A8ASP#30 does not include data flash memory. This is a defining distinction from the R5F102x series. The R5F103A8ASP#30 has only 4 KB of code flash and 512 B of RAM. For applications requiring non-volatile parameter storage, external EEPROM or FRAM must be added to the design.

How many UART channels does the R5F103A8ASP#30 support?

The R5F103A8ASP#30 supports exactly one UART channel (UART0). Unlike the R5F102Ax variants, it lacks UART1 and UART2. Pins P13 and P14 can be configured for UART2 functionality only in R5F102-series parts; on R5F103A8ASP#30, those pins default to secondary SPI/I²C or timer I/O roles.

What is the purpose of the REGC pin on the R5F103A8ASP#30?

The REGC pin (Pin 13) on the R5F103A8ASP#30 connects to the internal voltage regulator's stabilization capacitor. It must be tied to VSS via a 0.47–1 µF ceramic capacitor. Failure to do so risks unstable internal regulation, leading to erratic reset behavior or flash programming failures. This is mandatory per Renesas' electrical specifications and applies only to 30-pin LSSOP variants.

Can the R5F103A8ASP#30 operate from a 1.8 V supply?

Yes, the R5F103A8ASP#30 is fully specified to operate from 1.8 V to 5.5 V. At 1.8 V, the maximum allowed high-speed on-chip oscillator frequency is 16 MHz, and external crystal operation is limited to 8 MHz. All I/O tolerances, ADC reference stability, and reset thresholds remain guaranteed across this full voltage range.