Renesas R5F10266ASP#35

Overview

R5F10266ASP#35 from Renesas Electronics is a 20-pin RL78/G12 16-bit microcontroller designed for ultra-low-power embedded control in consumer-grade applications (–40°C to +85°C). It integrates 2 KB code flash, 256 B RAM, 2 KB data flash, 10-bit A/D converter (11 channels), and operates from 1.8 V to 5.5 V with true low-power consumption (63 μA/MHz). It is used in battery-powered sensor nodes and smart home peripherals requiring reliable on-chip timing, analog sensing, and serial communication.

For engineers reviewing the R5F10266ASP#35 datasheet, R5F10266ASP#35 pinout, R5F10266ASP#35 application, or R5F10266ASP#35 equivalent, this page delivers verified technical context, validated pin functions, real-world use cases, and confirmed alternative options - all aligned with Rev.2.50 of R01DS0193EJ0250 and Renesas' official ordering documentation.

Technical Context

The R5F10266ASP#35 implements the RL78 CPU core with CISC architecture and 3-stage pipeline, supporting minimum instruction execution time of 0.04167 µs at 24 MHz using the high-accuracy ±1.0% on-chip oscillator. Its memory subsystem includes 2 KB code flash (1 KB block size), 2 KB data flash with background operation (BGO), and 256 B RAM - with self-programming disabled per datasheet Note 2.

Peripheral integration includes 1-channel UART, 2-channel simplified SPI (CSI), 2-channel simplified I²C, 4-channel 16-bit timer (TAU0), 12-bit interval timer, watchdog timer, and CRC calculation unit. All I/O pins support N-ch open-drain (6 V tolerant on P21/P22), TTL input buffers, and on-chip pull-up resistors - enabling direct interfacing with 1.8/2.5/3.3 V logic.

Key Specifications

Pinout & Package

Package: 20-pin plastic TSSOP (4.4 × 6.5 mm, 0.65-mm pitch), RoHS-compliant, tray-packaged (#35).

Key Features

Applications

Equivalent & Alternatives

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

Compared with R5F10267ASP#35, the R5F10266ASP#35 trades RAM headroom for lower cost in fixed-function sensor nodes; versus R5F10366ASP#35, it retains critical data flash and tighter oscillator tolerance at modest premium - making it optimal for upgradeable, precision-constrained edge devices.

Availability

R5F10266ASP#35 is available at Aetrix Electronics and suitable for smart home sensor nodes, industrial panel meters, battery-powered access controllers, and USB-C power monitors requiring stable component supply and long-term production continuity.

Supply support for R5F10266ASP#35 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 global semiconductor leader delivering trusted embedded solutions for automotive, industrial, infrastructure, and IoT markets.

The RL78/G12 product line targets cost-sensitive, ultra-low-power general-purpose control applications - emphasizing energy efficiency, integrated analog peripherals, and rapid development with scalable memory options.

FAQ

What is the maximum operating frequency and instruction execution time for the R5F10266ASP#35?

The R5F10266ASP#35 supports a maximum high-speed on-chip oscillator frequency of 24 MHz, yielding a minimum instruction execution time of 0.04167 µs. This timing is achievable under HS mode with VDD ≥ 2.7 V. At lower supply voltages (1.8–2.4 V), the max oscillator frequency reduces to 16 MHz, extending execution time to 0.0625 µs. The RL78 core's 3-stage pipeline ensures deterministic performance across all supported clock configurations.

Does the R5F10266ASP#35 support self-programming of its code flash memory?

Yes, the R5F10266ASP#35 supports self-programming of its 2 KB code flash memory using the RL78 Family Flash Self Programming Library Type01. However, note that the self-programming function cannot be used simultaneously with the data flash function - both share resources, and the datasheet explicitly prohibits concurrent operation. Always consult the library user manual for memory layout constraints.

Can the R5F10266ASP#35 operate reliably at 1.8 V supply voltage?

Yes, the R5F10266ASP#35 is fully specified for operation from 1.8 V to 5.5 V. At 1.8 V, it supports high-speed on-chip oscillator frequencies up to 16 MHz and LS (low-speed main) mode up to 8 MHz. All peripherals - including the 10-bit A/D converter, UART, and timers - remain functional. The 63 μA/MHz active current figure applies across the full voltage range, confirming true low-voltage capability.

What are the key limitations of the 256 B RAM in the R5F10266ASP#35?

The 256 B RAM in the R5F10266ASP#35 limits stack depth and local variable allocation, especially when using the data flash library. As noted in the datasheet, insufficient RAM may prevent successful data flash write/erase operations. Developers must carefully manage stack usage and avoid deep function call nesting. For applications requiring robust BGO operation or larger state buffers, R5F10267ASP#35 (512 B RAM) is the recommended upgrade path.

How does the R5F10266ASP#35 handle analog reference voltage for the A/D converter?

The R5F10266ASP#35 provides dedicated AVREFP (P20) and AVREFM (P21) pins for the A/D converter reference. It includes an internal 1.45 V reference voltage source usable as VREF+ when external references are omitted. The 10-bit A/D converter supports single-ended and differential modes, with input voltage range constrained to 0 V to VDD or 0 V to AVREF(+) + 0.3 V - ensuring accurate measurements even with varying supply rails.