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STMicroelectronics STM8S903F3U6TR
- Part No.:
- STM8S903F3U6TR
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 20-UFQFN
- Datasheet:
-
STM8S903F3U6TR.pdf
- Description:
- IC MCU 8BIT 8KB FLASH 20UFQFPN
- Quantity:
- Payment:
- Shipping:
Inventory:2,250
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Product details
Overview
STM8S903F3U6TR from STMicroelectronics is an 8-bit microcontroller featuring a 16 MHz STM8 core, 8 Kbytes Flash, 1 Kbyte RAM, and 640 bytes EEPROM. It integrates a 10-bit ADC with 7 multiplexed channels, UART, SPI, I²C, and two 16-bit timers - deployed in industrial sensor nodes requiring low-power operation and robust I/O.
For engineers reviewing the STM8S903F3U6TR datasheet, STM8S903F3U6TR pinout, STM8S903F3U6TR application, or STM8S903F3U6TR equivalent, key selection criteria include its 20-pin UFQFPN package, 2.95–5.5 V supply range, nested interrupt controller supporting 32 interrupts, and integrated auto-wakeup timer for battery-powered monitoring systems.
Technical Context
The device implements a Harvard-architecture STM8 core with 3-stage pipeline and extended instruction set, enabling deterministic real-time execution. Its clock system includes four master sources: external crystal, external clock input, user-trimmable 16 MHz RC, and low-power 128 kHz RC - all managed by a clock security system with monitor.
Memory subsystem comprises 8 Kbytes of Flash (20-year data retention at 55 °C after 10 kcycles), 640 bytes of true data EEPROM (300 kcycle endurance), and 1 Kbyte RAM. Peripheral clock gating allows selective power-down of UART, SPI, I²C, ADC, and timers to minimize active-halt and wait-mode current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core | 16 MHz STM8 8-bit Harvard architecture with 3-stage pipeline and extended instruction set |
| Flash Memory | 8 Kbytes with 20-year data retention at 55 °C after 10,000 write/erase cycles |
| Data EEPROM | 640 bytes true data EEPROM, rated for 300,000 erase/write cycles |
| ADC | 10-bit ±1 LSB ADC with up to 7 external analog inputs + 1 internal channel, scan mode, analog watchdog |
| Timers | 16-bit advanced control timer (TIM1) with 4 CAPCOM channels and dead-time insertion; 16-bit general-purpose timer (TIM5); 8-bit basic timer (TIM6) |
| Communication | UART with SmartCard/IrDA/LIN master support; SPI up to 8 Mbit/s; I²C up to 400 kbit/s |
| Supply Voltage | 2.95 V to 5.5 V - supports direct interface with 3.3 V and 5 V logic domains without level shifters |
Pinout & Package
STM8S903F3U6TR is packaged in a 20-lead UFQFPN (3 × 3 mm, 0.5 mm pitch), optimized for space-constrained PCB layouts and thermal performance in industrial modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power supply | Main 2.95–5.5 V supply rail; decoupling capacitor required at pin |
| VSS | Ground | Digital ground reference; separate connection recommended from analog ground if used |
| NRST | Reset input | Active-low reset with internal pull-up; accepts external reset signal or power-on reset circuit |
| PA0–PA7 | General-purpose I/O | 8-bit port A with high-sink capability (20 mA per pin), configurable as digital I/O or alternate functions (e.g., UART TX/RX, SPI, ADC) |
| PB0–PB5 | General-purpose I/O | 6-bit port B with 21 high-sink outputs total across ports; supports remappable alternate functions including TIM1, I²C, and ADC triggers |
| SWIM | Single-wire interface | Debug and programming interface using single pin; enables in-circuit programming and real-time debugging |
Key Features
| Feature | Design Value |
|---|---|
| Low-power modes | Wait, active-halt, and halt modes with individual peripheral clock gating - reduces current to 0.3 µA in halt mode (VDD = 3.3 V) |
| Robust I/O design | 21 high-sink outputs (20 mA each) immune to current injection - eliminates need for external buffer drivers in relay/LED control |
| Integrated clock security | Clock monitor detects failure of main oscillator and automatically switches to backup 128 kHz RC - ensures fail-safe operation in safety-critical sensing |
| True data EEPROM | 640 bytes of dedicated EEPROM with 300 kcycle endurance - enables reliable parameter storage without Flash wear management overhead |
| 96-bit unique ID | Factory-programmed serial number per device - supports secure device authentication and firmware binding in OEM deployments |
Applications
| Industrial Sensor Node | Smart Metering Interface |
|---|---|
Use Scenario: Battery-powered temperature/humidity sensor with periodic wake-up and wireless transmission. IC Role / Device Role / Timing Role: Main controller executing sensor readout, ADC conversion, data formatting, and UART-to-LoRaWAN bridge timing. Use Value: Auto-wakeup timer and sub-µA halt-mode current enable multi-year battery life; integrated UART and SPI eliminate external transceiver logic. |
Use Scenario: Pulse-counting interface between mechanical utility meter and RF module. IC Role / Device Role / Timing Role: Edge-detecting I/O controller capturing meter pulses, timestamping via TIM5, and buffering counts for upstream transmission. Use Value: High-sink I/O drives optocoupler inputs directly; 10-bit ADC monitors supply voltage for low-battery alert without external components. |
| Home Appliance Control Panel | Motorized Actuator Module |
Use Scenario: Keypad and LED display controller in washing machine UI board. IC Role / Device Role / Timing Role: Scan matrix keypad, drive 7-segment LEDs via GPIO multiplexing, manage buzzer tone timing. Use Value: 28 I/Os on 32-pin variants (not applicable here) - but UFQFPN20 provides sufficient pins for 4×4 keypad + 8-segment display + status LEDs in compact layout. |
Use Scenario: Position feedback and commutation control in BLDC fan actuator. IC Role / Device Role / Timing Role: ADC reads hall-effect sensors; TIM1 generates complementary PWM with dead-time for gate driver ICs. Use Value: TIM1's 3 complementary outputs + dead-time insertion enable direct driving of 3-phase inverter bridges without external logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM8S003F3P6 | Same 20-pin UFQFPN package, identical core and peripherals, but only 1 Kbyte RAM and no true data EEPROM (uses Flash for emulated EEPROM) | Limited to simpler control tasks without persistent parameter storage; lower cost where EEPROM endurance is not required | Select when budget constraints outweigh need for dedicated EEPROM and higher RAM is unnecessary |
| EFM8BB10F8G-A-QFN20 | Silicon Labs 8051-based MCU in same 20-pin QFN; 8 Kbytes Flash, 512 bytes RAM, no integrated EEPROM; USB interface instead of SWIM | Requires external USB-to-UART bridge for programming; lacks hardware ADC watchdog and clock security monitor | Prefer when USB host connectivity is mandatory and SWIM debug infrastructure is unavailable |
Compared with STM8S903F3U6TR, STM8S003F3P6 trades EEPROM reliability and RAM headroom for lower unit cost, while EFM8BB10F8G-A-QFN20 replaces SWIM debug simplicity and clock fault resilience with USB-native programming - making STM8S903F3U6TR optimal for field-deployed industrial devices needing long-term data integrity and fail-safe timing.
Availability
STM8S903F3U6TR is available at Aetrix Electronics and suitable for industrial sensor nodes, smart metering interfaces, home appliance control panels, and motorized actuator modules requiring stable component supply across multi-year production cycles.
Supply support for STM8S903F3U6TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and automotive-grade components.
The STM8S series targets cost-sensitive, low-power industrial and consumer control applications - emphasizing robustness, ease of development, and long-term supply stability for embedded systems with moderate processing needs.
FAQ
What is the maximum operating frequency of the STM8S903F3U6TR?
The STM8S903F3U6TR operates at up to 16 MHz CPU frequency, supported across its full 2.95–5.5 V supply range. This maximum is guaranteed per electrical characteristics Table 21 and validated under worst-case process/voltage/temperature conditions - enabling deterministic real-time response in time-critical control loops without dynamic frequency scaling.
Does the STM8S903F3U6TR support in-system programming via SWIM?
Yes, the STM8S903F3U6TR supports single-wire in-circuit programming and debugging via the SWIM interface using one dedicated pin (pin 13 in UFQFPN20). No external bootloader is required - factory-programmed ROM loader enables firmware updates directly over SWIM with standard ST-LINK/V2 or compatible debuggers.
How many I/O pins are available in the UFQFPN20 package?
The STM8S903F3U6TR in UFQFPN20 provides 16 GPIO pins: PA0–PA7 (8 pins) and PB0–PB5 (6 pins), plus SWIM and NRST - totaling 18 usable signal pins. All GPIOs support alternate functions including UART, SPI, I²C, ADC, and timer channels, with 21 high-sink outputs available across the full STM8S903 family (realized on larger packages).
Is there hardware support for LIN bus communication?
Yes, the integrated UART1 peripheral supports LIN 2.2 master mode with automatic sync-break generation, checksum calculation, and identifier filtering - implemented entirely in hardware without CPU intervention. This enables compliant LIN node implementation for automotive body electronics and industrial distributed control networks.
STM8S903F3U6TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 20-UFQFN
- Series:
- STM8S
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Core Processor:
- STM8
- Core Size:
- 8-Bit
- Speed:
- 16MHz
- Connectivity:
- I2C, IrDA, LINbus, SPI, UART/USART
- Peripherals:
- Brown-out Detect/Reset, POR, PWM, WDT
- Number of I/O:
- 16
- Program Memory Size:
- 8KB (8K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- 640 x 8
- RAM Size:
- 1K x 8
- Voltage - Supply (Vcc/Vdd):
- 2.95V ~ 5.5V
- Data Converters:
- A/D 5x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
STM8S903F3U6TR FAQ
1.How can I place an order for STM8S903F3U6TR through Aetrix?
Please submit a Request for Quotation (RFQ) for STM8S903F3U6TR 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 STM8S903F3U6TR reliable?
The price and inventory of STM8S903F3U6TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM8S903F3U6TR is usually 5 days.
3.What payment methods are accepted for STM8S903F3U6TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM8S903F3U6TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM8S903F3U6TR?
STM8S903F3U6TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM8S903F3U6TR 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 STM8S903F3U6TR?
For technical support, including STM8S903F3U6TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM8S903F3U6TR requirements.
6.How does Aetrix verify that STM8S903F3U6TR is sourced from the original manufacturer or authorized distributors?
All STM8S903F3U6TR 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 STM8S903F3U6TR meets industry standards.
7.What is the process for return or replacement of STM8S903F3U6TR?
All STM8S903F3U6TR units undergo pre-shipment inspection (PSI). If there is an issue with STM8S903F3U6TR, 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 STM8S903F3U6TR part is unused and in its original packaging.
Return procedure for STM8S903F3U6TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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