Renesas R5F21284SDSP#U0

Overview

R5F21284SDSP#U0 from Renesas Electronics is a 16-bit R8C/28 Group single-chip microcontroller in 20-pin LSSOP package, featuring 16 KB flash program memory, 1 KB RAM, and 10-bit 4-channel ADC. It operates at up to 20 MHz (50 ns min instruction time), supports UART0/UART1, I²C, LIN, and timer peripherals including Timer RC (16-bit) and Timer RE (real-time clock), and targets industrial control and appliance applications.

For engineers reviewing the R5F21284SDSP#U0 datasheet, R5F21284SDSP#U0 pinout, R5F21284SDSP#U0 application, or R5F21284SDSP#U0 equivalent, key selection criteria include its -40°C to +85°C operating range (D version), integrated voltage detection and power-on reset, low-power stop mode (0.7 µA), and hardware LIN compliance via UART0 and Timer RA.

Technical Context

The R5F21284SDSP#U0 implements the R8C CPU core with 89 fundamental instructions and a 1 Mbyte address space. Its memory subsystem includes on-chip flash (16 KB program ROM) and SRAM (1 KB), with no data flash-distinguishing it from R8C/29 Group variants. The MCU integrates three independent clock generation circuits: XIN-based (up to 20 MHz), high-speed on-chip oscillator (adjustable), and XCIN-based 32 kHz circuit (D version only).

Peripheral integration includes dual UARTs (UART0 with LIN support, UART1), I²C bus interface, 8-bit Timers RA/RB, 16-bit Timer RC with input capture/output compare, and Timer RE with real-time clock functionality. All I/O ports are CMOS-compatible with programmable direction and pull-up control, and P1_0–P1_7 serve as LED drive ports in D-version devices.

Key Specifications

Pinout & Package

Package: 20-pin molded-plastic LSSOP (PLSP0020JB-A), 0.65 mm pitch, surface-mount.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit microcontroller applications.

Compared with R5F21284JSP#U0, the R5F21284SDSP#U0 adds XCIN/XCOUT support for precise RTC operation; versus R5F21294SDSP#U0, it trades data flash capacity for lower cost and simpler memory management in fixed-parameter systems.

Availability

R5F21284SDSP#U0 is available at Aetrix Electronics and suitable for industrial control systems, home appliance mainboards, and automotive body electronics requiring stable component supply across extended product lifecycles.

Supply support for R5F21284SDSP#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 global semiconductor leader specializing in microcontrollers, analog, and power solutions for industrial, automotive, and IoT markets.

The R8C/28 Group, including R5F21284SDSP#U0, was designed for cost-sensitive, reliability-critical embedded control in appliances and industrial equipment-emphasizing integration, low-power operation, and automotive-ready peripherals like LIN.

FAQ

What is the maximum operating frequency of the R5F21284SDSP#U0?

The R5F21284SDSP#U0 supports a maximum XIN input frequency of 20 MHz, enabling a minimum instruction execution time of 50 ns under VCC = 3.0–5.5 V conditions. This frequency is validated for continuous operation within its specified -40°C to +85°C ambient temperature range and defines the upper bound for timer resolution, UART baud rate generation, and ADC sampling throughput in the R5F21284SDSP#U0.

Does the R5F21284SDSP#U0 include on-chip data flash memory?

No, the R5F21284SDSP#U0 belongs to the R8C/28 Group and contains only program flash memory (16 KB) and SRAM (1 KB). It does not integrate data flash-unlike R8C/29 Group members such as R5F21294SDSP#U0, which provide 2 KB of data flash (1 KB × 2 blocks) with 10,000 write/erase cycles. Data storage in R5F21284SDSP#U0 must use external EEPROM or SRAM with backup power.

Which pins on the R5F21284SDSP#U0 support hardware LIN communication?

The R5F21284SDSP#U0 implements hardware LIN 2.0/2.1 using UART0 combined with Timer RA, with dedicated pins P1_4 (TXD0) and P1_5 (RXD0) serving as the LIN bus physical layer interface. These pins are electrically compatible with standard LIN transceivers and support automatic sync-break detection and checksum validation in firmware-controlled LIN frame handling.

What is the function of the XCIN and XCOUT pins on the R5F21284SDSP#U0?

The XCIN and XCOUT pins on the R5F21284SDSP#U0 provide a dedicated 32 kHz crystal oscillator interface for Timer RE's real-time clock function. This circuit is enabled only in D and N versions (not J/K), allowing accurate timekeeping independent of the main XIN clock. XCIN accepts a 32.768 kHz tuning-fork crystal, and XCOUT delivers the buffered output to complete the oscillator loop.

How many analog input channels does the R5F21284SDSP#U0 ADC support?

The R5F21284SDSP#U0 integrates a single 10-bit successive-approximation A/D converter with four analog input channels: AN8, AN9, AN10, and AN11-mapped to pins P1_0, P1_1, P1_2, and P1_3 respectively. Each channel supports programmable sampling time and conversion trigger sources including software, timer, or external interrupt, enabling synchronized multi-channel acquisition in the R5F21284SDSP#U0.