R5F21164SP#U0 - 16-Bit 20MHz Flash MCU | Renesas
MPN: R5F21164SP#U0 ✓ ActiveR5F21164SP#U0 Overview
A microcontroller is a semiconductor device that combines a processor core, memory, and peripherals on one integrated circuit. In the product hierarchy, the R5F21164SP#U0 is an MCU, part of the broader embedded-processing and semiconductor category. Its R8C CPU core supports compact, instruction-efficient control software, while flash memory permits the programmed firmware to remain resident without an external memory chip. The 20-LSSOP package also keeps the footprint suitable for space-constrained boards.
The device's principal specifications include a 16-bit R8C/1x/16 core, a 20 MHz maximum operating frequency, 16 KB of internal flash memory, and a 3 V to 5 V operating supply. Renesas describes the R8C/16 group as a non-promotion series supported for customers that previously adopted these products, with the RL78/G12 group recommended for new designs. This makes the MCU particularly relevant to maintenance and lifecycle-extension programs for established R8C platforms rather than first-generation greenfield projects.
The R8C architecture emphasizes instruction efficiency and provides a practical balance between processing capability, memory organization, and low-cost embedded integration. Flash-programmable firmware storage simplifies field updates and avoids the need for a parallel external program-memory device in designs that fit within the internal memory capacity. The silicon gate CMOS process supports integration of the CPU, memory, and control peripherals in a compact molded package suitable for industrial electronics.
Typical applications include industrial control panels, small motor and actuator controllers, sensor-interface nodes, programmable instruments, communication modules, and compact consumer or building-control products. In these systems, the MCU can execute control logic, monitor digital and analog inputs, manage outputs, and coordinate communications through its integrated peripherals. Its small package also helps reduce board area when compared with larger microcontroller packages.
Designers should begin by checking the complete peripheral allocation, interrupt structure, memory map, and electrical limits in the manufacturer datasheet before assigning pins or designing the PCB. The 20-pin package constrains the number of simultaneously available I/O functions, so multiplexed peripheral assignments and board-level interface requirements deserve early validation. Software compatibility with existing R8C tools and established firmware should also be confirmed during component planning.
This product page consolidates the manufacturer positioning, distributor identification, package information, verified operating characteristics, and practical selection guidance for engineers maintaining R8C-based equipment. It also distinguishes legacy-support considerations from the manufacturer's recommendation for RL78/G12 in new designs, helping procurement and engineering teams make an informed decision without confusing a functional MCU alternative with a verified pin-compatible replacement.
Drop-in alternatives for R5F21164SP#U0 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesR5F21164SP#U0 Maximum Ratings & Electrical Characteristics
| Product Type | 16-bit embedded microcontroller |
| Product Series | R8C/16 |
| CPU Core | R8C/Tiny Series R8C core |
| Processor Bit Width | 16 bit |
| Maximum Operating Frequency | 20 MHz |
| Internal Flash Memory | 16 KB |
| Flash Organization | 16K x 8 |
| Program Memory Type | Internal flash |
| Operating Supply Voltage | 3 V to 5 V |
| Process Technology | High-performance silicon gate CMOS |
| Package | 20-pin plastic molded LSSOP |
| Mounting Type | Surface mount |
| Lead-Free Status | Pb-free |
R5F21164SP#U0 20-pin plastic molded lssop Pin Configuration Guide
Pin configuration for R5F21164SP#U0 (20-pin plastic molded lssop package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for R5F21164SP#U0.
Refer to the datasheet for full pin configuration.
Typical Applications
R5F21164SP#U0 is suitable for 6 applications: Industrial Control Panels, Sensor Interface Nodes, Programmable Instruments, Communication Equipment, Small Motor and Actuator Controllers, Building and Automation Controls.
Industrial Control Panels
The R5F21164SP#U0 fits compact industrial control panels that require deterministic embedded control without a large processor module. Its 16-bit R8C/1x/16 core runs at up to 20 MHz, providing more arithmetic and addressing capability than an 8-bit controller, while 16 KB of internal flash holds application firmware. Place the MCU near the panel input and output circuitry to reduce routing distance. Because the 20-LSSOP package limits pin availability, validate every required switch, indicator, sensor, and communication signal against the datasheet pin table before layout.
Recommended
Sensor Interface Nodes
The R5F21164SP#U0 can serve as the control center for a small sensor-interface node that gathers digital inputs, processes measurements, and reports operating status. Its 20 MHz R8C core supports responsive firmware for sampling sequences, filtering, diagnostics, and communication tasks, while integrated 16 KB flash removes the need for an external program-memory device when firmware fits. The 3 V to 5 V operating range aligns with common embedded sensor architectures. Verify analog-capable pins, input thresholds, and communications pins in the manufacturer datasheet before finalizing the sensor board.
Recommended
Programmable Instruments
The R5F21164SP#U0 is appropriate for programmable instruments where a compact MCU must coordinate controls, displays, measurements, and communications. The 16-bit architecture and 20 MHz maximum clock support efficient handling of instrument commands and control sequences, while internal flash stores the firmware needed after power-up. Its 20-LSSOP package helps limit board size in bench instruments and embedded test equipment. Design the front end around the MCU's verified peripheral functions and isolate analog signal paths from fast digital switching to preserve measurement quality.
Recommended
Communication Equipment
The R5F21164SP#U0 can act as the supervisory controller in compact communication equipment, handling configuration, status monitoring, and low-level protocol handling. Its 16-bit R8C core executes at up to 20 MHz, providing enough throughput for coordination tasks while the 16 KB flash retains resident firmware. The 3 V to 5 V supply range supports integration into conventional embedded systems. Select serial and bus functions only after checking alternate-function mapping in the 20-LSSOP pinout, then isolate communications routing from sensitive timing or power-conversion circuitry.
Recommended
Small Motor and Actuator Controllers
The R5F21164SP#U0 is suitable for compact actuator and small-motor controller logic where sequencing, timing, fault handling, and user commands must be coordinated in real time. Its 20 MHz R8C core provides responsive task execution, and the 16 KB internal flash stores control firmware close to the processor. Use the MCU for command logic and low-current control signaling while assigning power-stage switching to appropriately rated external circuitry. Confirm timer availability, output-drive limits, and start-up behavior in the datasheet to avoid overloading device pins.
Recommended
Building and Automation Controls
The R5F21164SP#U0 can be used in compact building-control nodes for lighting interfaces, environmental monitoring, access-control logic, and equipment coordination. Its low-pin-count LSSOP package supports space-constrained distributed electronics, while the 16-bit core and 20 MHz clock provide adequate throughput for event handling and supervisory software. Internal flash allows field-oriented firmware to remain resident in the node. Plan power-loss behavior, communication isolation, and I/O protection carefully, and verify the exact operating-temperature and ESD requirements for the installation environment.
Recommended
Recommended Products Summary
Engineering reference data for R5F21164SP#U0 — comparison, design guidance, and compliance information.
Selection Guide
Design Notes
Confirm the 20-LSSOP land pattern and pin sequence against the Renesas package drawing before routing the PCB. The R5F21164SP#U0 combines limited I/O availability with multiplexed peripheral functions, so allocate pins for power, ground, programming, reset, and communications before assigning application signals. Keep traces to sensitive analog inputs away from switching nodes and high-current return paths. A short ground reference and a low-impedance supply-plane connection will improve signal and power integrity.
Decouple each device supply connection with the capacitance and placement required by the manufacturer datasheet, and route the loop through the nearest ground reference rather than through a distant plane connection. Separate noisy switching or motor-current returns from sensitive analog inputs. Do not infer the allowable input voltage, output-drive strength, or injection limits from generic 3 V to 5 V logic assumptions; verify them in the electrical-characteristics tables before attaching external signals.
Do not treat the 16 KB flash figure as the device's complete memory capacity. Confirm internal RAM, program-memory organization, address space, peripheral resources, and interrupt requirements in the datasheet. The R8C/16 group is described by Renesas as a non-promotion family, so an existing design should also verify toolchain availability, programming support, and ongoing component supply. A board redesign is preferable to assuming that a different MCU family can replace this part without pin and firmware validation.
Compliance Information
Distributor product information identifies the R5F21164SP#U0 as Pb-free. RoHS, REACH, halogen-free, and conflict-minerals status are not stated in the available product descriptions. AEC-Q100 is treated as not applicable because the product is not identified as an automotive-qualified device.
