Renesas R5F10278ANA#U0

Overview

R5F10278ANA#U0 from Renesas Electronics is a 24-pin HWQFN-packaged RL78/G12 16-bit microcontroller with 8 KB code flash, 2 KB data flash, and 512 B RAM, operating at 1.8–5.5 V with true low-power modes (63 μA/MHz), used in battery-powered industrial sensors and consumer appliance control.

For engineers reviewing the R5F10278ANA#U0 datasheet, R5F10278ANA#U0 pinout, R5F10278ANA#U0 application, or R5F10278ANA#U0 equivalent, key selection criteria include its integrated 2 KB data flash for firmware updates, 2-channel DMA for sensor data offload, 10-bit 11-channel ADC for analog monitoring, and hardware CRC for firmware integrity in resource-constrained embedded systems.

Technical Context

The R5F10278ANA#U0 implements the RL78 CPU core with 3-stage pipeline and supports dual-clock operation: high-speed on-chip oscillator (1–24 MHz, ±1.0% accuracy at –20 to +85°C) and external crystal (1–20 MHz). It integrates a 12-bit interval timer, window watchdog timer, and on-chip voltage detector with 12 selectable reset thresholds.

Its peripheral set includes UART0, CSI00/CSI01 (Simplified SPI), IIC00/IIC01 (Simplified I²C), TAU0 with four 16-bit timer channels, and SAU0 supporting serial communication and PWM generation - all configurable via Peripheral I/O Redirection Register (PIOR) without hardware changes.

Key Specifications

Pinout & Package

Package: HWQFN-24 (4 × 4 mm, 0.5 mm pitch), exposed die pad recommended to be connected to VSS for thermal and electrical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with R5F10279ANA#U0, the R5F10278ANA#U0 trades 4 KB flash for lower cost and smaller footprint; compared with R5F10378ANA#U0, it adds critical reliability features (data flash, CRC, DMA) essential for certified industrial deployments.

Availability

R5F10278ANA#U0 is available at Aetrix Electronics and suitable for smart home controllers, industrial sensor nodes, and portable medical devices requiring stable component supply across extended production lifecycles.

Supply support for R5F10278ANA#U0 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 IoT markets.

The RL78/G12 product line delivers ultra-low-power 16-bit MCUs optimized for cost-sensitive, battery-operated embedded applications requiring robust peripheral integration and long-term supply assurance.

FAQ

What is the maximum operating frequency of the R5F10278ANA#U0?

The R5F10278ANA#U0 supports a maximum system clock frequency of 24 MHz using its high-speed on-chip oscillator. When using an external crystal, the maximum main system clock frequency is 20 MHz. The minimum instruction execution time is 0.04167 µs at 24 MHz, enabling real-time response in time-critical control loops. All timing specifications assume VDD ≥ 2.7 V for full-speed operation.

Does the R5F10278ANA#U0 include hardware debug support?

Yes, the R5F10278ANA#U0 includes an on-chip debug function compatible with Renesas E2 emulator and CS+ IDE. It supports full-speed debugging, breakpoint setting, and memory inspection via the TOOL0/TOOLRxD/TOOLTxD interface. However, Renesas advises against using the debug function in mass-produced end products due to potential flash endurance impact from repeated programming cycles.

Can the R5F10278ANA#U0 operate from a 1.8 V supply?

Yes, the R5F10278ANA#U0 is fully specified for operation from 1.8 V to 5.5 V. At 1.8 V, it supports low-speed main mode (up to 8 MHz) and retains full functionality of its 10-bit ADC, UART, timers, and I/O ports. The 63 μA/MHz active current and 0.52 μA STOP mode current are guaranteed across this voltage range, making it ideal for single-cell Li-ion or alkaline battery systems.

How many analog input channels does the R5F10278ANA#U0 support?

The R5F10278ANA#U0 supports 11 analog input channels (ANI0–ANI3, ANI16–ANI22) with 10-bit resolution and internal 1.45 V reference voltage. Channels ANI0 and ANI1 double as AVREFP and AVREFM for differential measurement. The ADC operates across the full 1.8–5.5 V supply range and includes temperature sensor output for system health monitoring.

Is the R5F10278ANA#U0 pin-compatible with other RL78/G12 variants?

Yes, the R5F10278ANA#U0 is pin-compatible with all 24-pin HWQFN variants in the RL78/G12 family, including R5F10277ANA#U0, R5F10279ANA#U0, and R5F10378ANA#U0. Pin assignments, power/ground locations, and peripheral multiplexing are identical across these parts, enabling drop-in replacement for memory or feature upgrades - provided PCB layout accommodates the exposed die pad connection to VSS.