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Renesas R5F21181DSP#U0
- Part No.:
- R5F21181DSP#U0
- Manufacturer:
- Renesas
- Category:
- Microcontrollers
- Package:
- 20-LSSOP (0.173", 4.40mm Width)
- Datasheet:
-
R5F21181DSP#U0.pdf
- Description:
- IC MCU 16BIT 4KB FLASH 20LSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,433
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Product details
Overview
R5F21181DSP#U0 from Renesas Electronics is a 16-bit single-chip CMOS microcontroller in the R8C/18 Group, featuring an R8C/Tiny Series CPU core, 4 KB flash program memory, 384 bytes RAM, and operation at up to 20 MHz (50 ns min instruction time). It integrates timer peripherals (Timer X/Z/C), UART and clock-synchronous serial I/O, 1-bit comparator (4 channels), watchdog timer, and 13 I/O pins - designed for embedded control in household appliances and industrial sensors.
For engineers reviewing the R5F21181DSP#U0 datasheet, R5F21181DSP#U0 pinout, R5F21181DSP#U0 application, or R5F21181DSP#U0 equivalent, this page delivers verified specifications, package mapping to PLSP0020JB-A (20-pin LSSOP), validated pin functions, real-world use cases, and two confirmed alternative parts with documented functional and parametric differences.
Technical Context
The R5F21181DSP#U0 implements a 16-bit R8C/Tiny CPU with 89 fundamental instructions and a 20-bit program counter supporting 1 Mbyte address space. Its memory subsystem includes on-chip flash ROM (4 KB) and SRAM (384 B), with no data flash - distinguishing it from R8C/19 Group variants.
Peripherals include three timers (8-bit Timer X/Z with 8-bit prescaler; 16-bit Timer C with input capture/output compare), dual UART channels, one clock-synchronous serial interface, and a 4-channel 1-bit comparator. It supports single-chip operation with integrated power-on reset, voltage detection, and main clock oscillation stop detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| CPU Core | R8C/Tiny 16-bit, 89 instructions, 20-bit PC - enables compact code and deterministic real-time execution |
| Flash Memory | 4 KB program ROM - sufficient for small firmware images with field-upgradable capability |
| RAM | 384 bytes - supports stack, variables, and small buffers without external memory |
| Max Clock Speed | 20 MHz (50 ns min instruction time at VCC = 3.0–5.5 V) - balances performance and low-power operation |
| Operating Temp | −40°C to +85°C (D version) - qualified for industrial environments with extended thermal range |
| Supply Voltage | 2.7–5.5 V - compatible with both 3.3 V and 5 V system rails |
| I/O Pins | 13 configurable CMOS I/O (including 4 LED drive ports) - supports direct LED interfacing and sensor readout |
| Interrupt Sources | 10 internal + 4 external + 4 software sources, 7 priority levels - enables responsive multi-tasking in resource-constrained systems |
Pinout & Package
Package: 20-pin molded-plastic LSSOP (PLSP0020JB-A), 0.65 mm pitch, surface-mount, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (P3_5) | Comparator output | CMP1_2 - dedicated comparator channel output for analog threshold detection |
| 2 (P3_7) | Timer/serial I/O | CNTR0 / TXD1 - supports timer input capture or UART transmit function |
| 3 (RESET) | Reset input | Active-low asynchronous reset - initiates hardware initialization sequence |
| 4 (XOUT) | Oscillator output | Main clock oscillator output - drives external crystal/resonator feedback path |
| 5 (VSS/AVSS) | Ground | Digital and analog ground reference - requires separate decoupling for noise-sensitive analog functions |
| 6 (XIN) | Oscillator input | Main clock oscillator input - accepts crystal, ceramic resonator, or external clock signal |
| 7 (VCC/AVCC) | Power supply | Digital and analog supply (2.7–5.5 V) - AVCC must be filtered for stable comparator operation |
| 8 (MODE) | Boot mode select | Must be pulled high via resistor - determines startup vector and flash boot configuration |
| 9 (P4_5) | Interrupt/serial I/O | INT0 / RXD1 - supports external interrupt trigger or UART receive input |
| 10 (P1_7) | Timer/interrupt I/O | CNTR00 / INT10 - timer counter input or external interrupt source |
| 11 (P1_6) | Serial clock I/O | CLK0 - bidirectional transfer clock for synchronous serial communication |
| 12 (P1_5) | Serial I/O/interrupt | RXD0 / CNTR01 / INT11 - UART receive, timer input, or interrupt request |
| 13 (P1_4) | Serial output | TXD0 - UART transmit output - drives RS-232/RS-485 level shifters or logic-level peripherals |
| 14 (P1_3) | Key input/timer output | KI3 / TZOUT / AN11 - supports key scan, timer waveform output, or analog comparator input |
| 15 (P1_2) | Key input/comparator | KI2 / CMP0_2 / AN10 - enables keypad interface and analog sensing on same pin |
| 16 (VREF) | Analog reference | Comparator reference voltage input - sets threshold for all four comparator channels |
| 17 (P1_1) | Key input/comparator | KI1 / CMP0_1 / AN9 - shared functionality reduces BOM count in sensor-keypad designs |
| 18 (P1_0) | Key input/comparator | KI0 / CMP0_0 / AN8 - primary analog input and key detection pin |
| 19 (P3_3) | Timer/interrupt/comparator | TCIN / INT3 / CMP1_0 - timer C input, external interrupt, or comparator channel |
| 20 (P3_4) | Comparator output | CMP1_1 - second output of comparator group 1 - supports multi-threshold monitoring |
Key Features
| Feature | Design Value |
|---|---|
| Integrated voltage detector | On-chip circuit monitors VCC and triggers reset if supply drops below threshold - eliminates external supervisor IC |
| Low-power stop mode | 0.7 µA typical current at 3.0 V - extends battery life in always-on sensor nodes |
| Hardware UART + synchronous serial | Dual serial interfaces enable simultaneous host communication and peripheral daisy-chaining - no software bit-banging required |
| LED drive ports | 4 I/O pins support direct LED connection with current-limiting capability - simplifies front-panel indicator design |
| Comparator with shared analog inputs | 4-channel 1-bit comparator reuses AN8–AN11 pins - enables multi-point threshold detection without ADC overhead |
| High-speed on-chip oscillator | Adjustable internal RC oscillator - provides clock source during crystal startup or as backup when external clock fails |
Applications
| Home Appliance Control | Industrial Sensor Node |
|---|---|
|
Use Scenario: Microcontroller in washing machine control board managing motor sequencing, water valve timing, and user interface. IC Role / Device Role / Timing Role: Primary system controller executing real-time state machine, driving LEDs, reading push buttons, and communicating with display module via UART. Use Value: Integrated 4 KB flash and 384 B RAM eliminate external memory; LED drive ports reduce discrete component count; −40°C to +85°C rating ensures reliability in humid cabinet environments. |
Use Scenario: Standalone temperature/humidity sensor node transmitting data wirelessly via UART-connected transceiver. IC Role / Device Role / Timing Role: Data acquisition engine sampling analog sensors via comparator thresholds, managing low-power sleep/wake cycles, and formatting packets for transmission. Use Value: 0.7 µA stop-mode current extends battery life to >2 years; built-in voltage detector prevents brown-out corruption; UART interface directly connects to sub-GHz RF modules. |
| Office Equipment Monitor | Security System Keypad |
|
Use Scenario: Embedded controller in printer status panel monitoring paper jam, toner level, and error codes. IC Role / Device Role / Timing Role: Peripheral manager polling mechanical switches, driving status LEDs, and relaying alerts to main controller via UART. Use Value: 13 I/O pins accommodate multiple switches and indicators; KI0–KI3 key input interrupts enable fast response to button presses; 20 MHz speed ensures snappy UI updates. |
Use Scenario: Entry keypad unit validating PIN entries and triggering door lock actuation upon match. IC Role / Device Role / Timing Role: Secure input processor scanning matrix keypad, comparing entered digits against stored values, and asserting lock control signal. Use Value: Comparator channels detect tamper switches and power anomalies; integrated watchdog timer prevents firmware lockup; D-version temperature range supports outdoor mounting. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 16-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| R5F21182DSP#U0 | 8 KB flash, 512 B RAM - double program storage and data buffer capacity | Better suited for firmware with larger feature sets or bootloader requirements | Select when code size exceeds 4 KB or additional RAM is needed for communication stacks |
| R5F21191DSP#U0 | R8C/19 Group part with 1 KB × 2 data flash - supports EEPROM-like parameter storage | Required where field-updatable calibration data or user settings must persist across power cycles | Choose only if data flash functionality is mandatory; otherwise R5F21181DSP#U0 offers lower cost and identical peripheral set |
Compared with R5F21182DSP#U0 and R5F21191DSP#U0, the R5F21181DSP#U0 provides optimal cost/performance balance for fixed-function control tasks where code size stays under 4 KB and non-volatile parameter storage is handled externally or via software emulation.
Availability
R5F21181DSP#U0 is available at Aetrix Electronics and suitable for home appliance control, industrial sensor nodes, and office equipment monitoring requiring stable component supply and long-term industrial lifecycle support.
Supply support for R5F21181DSP#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, power, and SoC solutions for industrial, automotive, and consumer markets.
The R5F21181DSP#U0 belongs to the R8C/18 Group - a family of cost-optimized 16-bit MCUs designed for reliable, low-power embedded control in appliances, sensors, and human-interface devices.
FAQ
What is the maximum operating frequency of the R5F21181DSP#U0?
The R5F21181DSP#U0 operates at up to 20 MHz with a minimum instruction execution time of 50 ns when supplied at 3.0–5.5 V. This frequency is achieved using either the external crystal/resonator connected to XIN/XOUT or the internal high-speed oscillator with frequency adjustment enabled.
Does the R5F21181DSP#U0 include data flash memory?
No, the R5F21181DSP#U0 is part of the R8C/18 Group and contains only 4 KB of program flash memory and 384 bytes of RAM. It does not include data flash - that feature is exclusive to R8C/19 Group parts like R5F21191DSP#U0, which integrate 1 KB × 2 data flash blocks.
Which package type is used for the R5F21181DSP#U0?
The R5F21181DSP#U0 uses the PLSP0020JB-A package: a 20-pin molded-plastic LSSOP with 0.65 mm lead pitch. This package is pin-compatible with other R8C/18 Group variants in the same footprint, including R5F21182DSP#U0 and R5F21183DSP#U0.
What are the key low-power modes supported by the R5F21181DSP#U0?
The R5F21181DSP#U0 supports wait mode (35 µA typical at 3.0 V, peripheral clocks off) and stop mode (0.7 µA typical at 3.0 V). Stop mode halts the CPU and all peripherals while retaining RAM content and allowing wake-up via RESET, INT0–INT3, or KI0–KI3 - ideal for battery-powered standby operation.
Can the R5F21181DSP#U0 drive LEDs directly?
Yes, the R5F21181DSP#U0 features four dedicated LED drive ports (P1_0 to P1_3), each capable of sourcing/sinking sufficient current for standard indicator LEDs. These pins support both general-purpose I/O and LED drive functions without external drivers, reducing bill-of-materials cost.
R5F21181DSP#U0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Package/Case:
- 20-LSSOP (0.173", 4.40mm Width)
- Series:
- R8C/1x/18
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- R8C
- Core Size:
- 16-Bit
- Speed:
- 20MHz
- Connectivity:
- SIO, UART/USART
- Peripherals:
- LED, POR, Voltage Detect, WDT
- Number of I/O:
- 13
- Program Memory Size:
- 4KB (4K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 384 x 8
- Voltage - Supply (Vcc/Vdd):
- 2.7V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
R5F21181DSP#U0 FAQ
1.How can I place an order for R5F21181DSP#U0 through Aetrix?
Please submit a Request for Quotation (RFQ) for R5F21181DSP#U0 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for R5F21181DSP#U0 reliable?
The price and inventory of R5F21181DSP#U0 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for R5F21181DSP#U0 is usually 5 days.
3.What payment methods are accepted for R5F21181DSP#U0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for R5F21181DSP#U0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for R5F21181DSP#U0?
R5F21181DSP#U0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your R5F21181DSP#U0 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for R5F21181DSP#U0?
For technical support, including R5F21181DSP#U0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your R5F21181DSP#U0 requirements.
6.How does Aetrix verify that R5F21181DSP#U0 is sourced from the original manufacturer or authorized distributors?
All R5F21181DSP#U0 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that R5F21181DSP#U0 meets industry standards.
7.What is the process for return or replacement of R5F21181DSP#U0?
All R5F21181DSP#U0 units undergo pre-shipment inspection (PSI). If there is an issue with R5F21181DSP#U0, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The R5F21181DSP#U0 part is unused and in its original packaging.
Return procedure for R5F21181DSP#U0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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