Renesas R5F10278ANA#U5

Overview

R5F10278ANA#U5 from Renesas Electronics is an RL78/G12 24-pin HWQFN microcontroller with 8 KB code flash, 2 KB data flash, 768 B RAM, 10-bit A/D converter (11 channels), and dual serial interfaces (2× CSI, 2× I²C, 1× UART) - designed for ultra-low-power consumer-grade embedded control in battery-powered sensors and smart peripherals operating from 1.8 V to 5.5 V.

For engineers reviewing the R5F10278ANA#U5 datasheet, R5F10278ANA#U5 pinout, R5F10278ANA#U5 application, or R5F10278ANA#U5 equivalent, key selection criteria include its 24-pin HWQFN-0.5 mm package, integrated data flash for field firmware updates, 63 μA/MHz active current, and support for STOP/HALT/SNOOZE low-power modes in -40°C to +85°C ambient.

Technical Context

The R5F10278ANA#U5 implements the RL78 CPU core with a 3-stage CISC pipeline, 1 MB address space, and configurable instruction timing (0.04167 μs min @ 24 MHz). It integrates a high-accuracy ±1.0% on-chip oscillator (1–24 MHz selectable), CRC engine, RAM guard, and SFR guard - features exclusive to R5F102-series variants and absent in R5F103 counterparts.

Its peripheral set includes two DMA channels, TAU0 16-bit timer (4 channels), window watchdog, 12-bit interval timer, and programmable clock/buzzer output - all powered by a single-supply 1.8–5.5 V rail and managed via on-chip POR/LVD reset and voltage detection across 12 user-selectable thresholds.

Key Specifications

Pinout & Package

24-pin plastic HWQFN (PWQN0024KE-A / PWQN0024KF-A), 4 × 4 mm body, 0.5 mm pitch, exposed thermal pad (recommended connection to VSS).

Key Features

Applications

Equivalent & Alternatives

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

Compared with R5F10279ANA#U5, the R5F10278ANA#U5 trades 4 KB flash capacity for identical low-power behavior and peripheral integration; versus R5F10378ANA#U5, it adds data flash persistence, oscillator precision, and hardware safety - justifying its use in upgradable, safety-aware consumer devices.

Availability

R5F10278ANA#U5 is available at Aetrix Electronics and suitable for smart home sensor nodes, portable medical monitors, industrial control panels, and energy-efficient appliance MCUs requiring stable component supply across production lifecycles.

Supply support for R5F10278ANA#U5 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 is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, and IoT markets.

The RL78/G12 product line delivers true low-power embedded control for cost-sensitive consumer and industrial applications - emphasizing sub-100 μA/MHz efficiency, integrated data flash, and hardware safety features without external components.

FAQ

What is the maximum operating frequency of the R5F10278ANA#U5?

The R5F10278ANA#U5 supports a maximum high-speed on-chip oscillator frequency of 24 MHz and a maximum external crystal clock (X1) frequency of 20 MHz under 2.7–5.5 V supply conditions. At 24 MHz, its minimum instruction execution time is 0.04167 μs, delivering 31 DMIPS performance. The device also supports lower-frequency modes (1–8 MHz) for ultra-low-power operation down to 1.8 V.

Does the R5F10278ANA#U5 include data flash memory, and what is its endurance?

Yes, the R5F10278ANA#U5 includes 2 KB of on-chip data flash memory with 1,000,000 write/erase cycles (typical) and background operation (BGO) capability. This allows firmware to execute from code flash while concurrently rewriting data flash - essential for storing calibration data, device configuration, or usage logs without interrupting real-time operation.

What low-power modes does the R5F10278ANA#U5 support, and what are their typical current draws?

The R5F10278ANA#U5 supports HALT (0.52 μA), STOP (0.31 μA), and SNOOZE modes. HALT stops the CPU but keeps peripherals active; STOP disables most clocks for minimal leakage; SNOOZE allows selected peripherals (e.g., UART, CSI) to operate autonomously and wake the CPU on event. All modes retain RAM content and support fast wake-up (< 4 μs from HALT).

Can the R5F10278ANA#U5 interface directly with 1.8 V and 3.3 V peripherals?

Yes, the R5F10278ANA#U5 supports mixed-voltage I/O: its standard CMOS ports operate across 1.8–5.5 V, and pins P60/P61 are N-ch open-drain with 6 V tolerance - enabling direct connection to 1.8 V, 2.5 V, or 3.3 V I²C buses without external level shifters. Input buffers accept TTL-compatible thresholds, and port drive strength is configurable per pin.

Is the R5F10278ANA#U5 pin-compatible with other RL78/G12 24-pin variants?

Yes, the R5F10278ANA#U5 shares identical pinout and package (HWQFN-24) with all R5F1027x and R5F1037x variants - including R5F10279ANA#U5, R5F10277ANA#U5, and R5F10378ANA#U5. This enables footprint reuse across flash-size and feature-tier options, simplifying design scalability and inventory management for manufacturers targeting multiple product SKUs.