My Inquiry
My Account
STMicroelectronics STM8S903K3T3CTR
- Part No.:
- STM8S903K3T3CTR
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 32-LQFP
- Datasheet:
-
STM8S903K3T3CTR.pdf
- Description:
- IC MCU 8BIT 8KB FLASH 32LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:2,400
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
STM8S903K3T3CTR from STMicroelectronics is an 8-bit MCU with 8 Kbytes Flash, 1 Kbyte RAM, and 640 bytes EEPROM, featuring a 16 MHz STM8 core, 10-bit ADC (7 channels), UART/SPI/I²C interfaces, and dual 16-bit timers - deployed in industrial sensor nodes and motor control feedback loops.
For engineers reviewing the STM8S903K3T3CTR datasheet, STM8S903K3T3CTR pinout, STM8S903K3T3CTR application, or STM8S903K3T3CTR equivalent, key selection criteria include 32-pin LQFP/UFQFPN package compatibility, 2.95–5.5 V supply range, low-power active-halt mode (<1.5 µA), and SWIM single-wire debug interface support.
Technical Context
The STM8S903K3T3CTR implements a Harvard-architecture STM8 core with 3-stage pipeline and extended instruction set, enabling deterministic real-time execution at up to 16 MHz. Its clock system integrates four sources: external crystal, external clock input, user-trimmable 16 MHz RC, and low-power 128 kHz RC - all monitored by a clock security system.
Interrupt handling uses a nested controller supporting 32 vectors and up to 28 external interrupts across 7 priority levels. Memory subsystem includes 8 Kbytes Flash (20-year data retention at 55 °C), 640-byte true EEPROM (300 kcycle endurance), and 1 Kbyte RAM with hardware register mapping for peripheral control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | STM8 8-bit Harvard core with 3-stage pipeline and extended instruction set - enables deterministic timing for real-time control loops. |
| Max Clock Frequency | 16 MHz - supports high-speed UART (up to 1 Mbit/s), SPI (up to 8 Mbit/s), and I²C (up to 400 kbit/s) without CPU bottlenecking. |
| Flash Memory | 8 Kbytes Flash with 10 kcycle endurance and 20-year data retention at 55 °C - suitable for field-updatable firmware in long-lifecycle industrial devices. |
| Data EEPROM | 640 bytes true EEPROM with 300 kcycle write endurance - stores calibration data, device configuration, or runtime counters without external NV memory. |
| ADC Resolution | 10-bit SAR ADC with ±1 LSB INL, 7 multiplexed inputs + 1 internal channel - provides sufficient precision for temperature sensing, voltage monitoring, and analog sensor interfacing. |
| Supply Voltage Range | 2.95 to 5.5 V - allows direct operation from 3.3 V logic rails or legacy 5 V systems without level-shifting. |
| Low-Power Modes | Wait, active-halt (<1.5 µA typical), and halt modes - enables battery-powered operation for >1 year in sensor wake-on-event applications. |
Pinout & Package
LQFP32 (7 × 7 mm) and UFQFPN32 (5 × 5 mm) packages - both RoHS-compliant, surface-mount, with 0.8 mm (LQFP) or 0.5 mm (UFQFPN) pitch; pin-compatible across 32-pin variants per datasheet Section 5.4–5.5.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual power pins enable clean decoupling; VCAP capacitor required on VCAP pin for internal regulator stability. |
| NRST | Active-low reset input | Asynchronous reset with internal pull-up; supports external reset button or supervisor IC integration. |
| SWIM | Single-wire interface for programming/debug | Enables in-system programming and real-time debugging using only one GPIO - reduces debug footprint vs JTAG/SWD. |
| PA0–PA7, PB0–PB7, PC0–PC7, PD0–PD7 | General-purpose I/O ports | Up to 28 total I/Os; 21 support high-sink capability (20 mA), critical for driving LEDs or small relays directly. |
| CLK, CLKOUT | Master clock input/output | Accepts external crystal (1–16 MHz) or clock source; CLKOUT can drive secondary peripherals or test equipment. |
| UART1_TX, UART1_RX | Asynchronous serial interface | Full-duplex UART with LIN master mode, SmartCard, and IrDA support - used for host communication or firmware updates. |
Key Features
| Feature | Design Value |
|---|---|
| Advanced Control Timer (TIM1) | 16-bit timer with 4 CAPCOM channels, 3 complementary outputs, dead-time insertion - enables 3-phase motor gate drive without external logic. |
| Auto Wake-up Timer (AWU) | Configurable low-power wake-up from halt/wait modes using internal 128 kHz RC - eliminates need for external RTC in periodic-sensing applications. |
| Internal Reference Voltage Measurement | ADC internal channel measures VREFINT (1.22 V ±5%) - enables supply voltage monitoring and self-calibration without external components. |
| 96-bit Unique ID | Factory-programmed read-only identifier per device - supports secure device authentication and license binding in OEM firmware. |
| Flexible Clock Security System | Dedicated clock monitor detects HSE/HSI failure and triggers reset - prevents erratic behavior in safety-critical timing functions. |
Applications
| Industrial Sensor Node | Brushless DC Motor Controller |
|---|---|
|
Use Scenario: Compact environmental sensor unit measuring temperature, humidity, and supply voltage in factory-floor enclosures. IC Role / Device Role / Timing Role: Central data acquisition and preprocessing unit; executes ADC scans, UART telemetry bursts, and low-power sleep cycles. Use Value: Integrated 10-bit ADC, 640-byte EEPROM for calibration storage, and active-halt mode (<1.5 µA) extend battery life beyond 2 years. |
Use Scenario: Closed-loop commutation control for 3-phase BLDC motors in HVAC blowers and pump drives. IC Role / Device Role / Timing Role: Real-time motor timing engine; generates synchronized PWM signals with dead-time insertion via TIM1. Use Value: Hardware-level dead-time control and complementary outputs eliminate external gate-driver logic, reducing BOM count and PCB area. |
| Smart Meter Front-End | Home Appliance UI Controller |
|
Use Scenario: Energy meter sub-system acquiring voltage/current samples and communicating via UART to main processor. IC Role / Device Role / Timing Role: Dedicated metrology co-processor; handles ADC oversampling, digital filtering, and LIN bus messaging. Use Value: LIN master mode and 10-bit ADC with analog watchdog allow robust, noise-immune communication and fault detection in EMI-heavy utility environments. |
Use Scenario: Keypad, LED display, and buzzer management in washing machines and microwave ovens. IC Role / Device Role / Timing Role: Human interface manager; scans matrix keypad, drives 21 high-sink I/Os for LEDs, and controls beeper tone via TIM6. Use Value: 21 high-sink I/Os eliminate external driver transistors; integrated beeper module reduces component count and simplifies audio feedback design. |
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 STM8 core, but 8 Kbytes Flash, 1 Kbyte RAM, 128 bytes EEPROM; TSSOP20 (20-pin) package only - lacks TIM1 advanced timer and 32-pin I/O count. | Suitable for simpler UI or sensor tasks where 28 I/Os and motor control peripherals are unnecessary. | Select when cost and board space are primary constraints and advanced timer features are unused. |
| STM8L052C6T6 | Ultra-low-power STM8L variant: 32 Kbytes Flash, 2 Kbytes RAM, 1 Kbyte EEPROM; operates down to 1.8 V; consumes <0.35 µA in halt mode. | Targeted at battery-powered IoT endpoints requiring multi-year operation - trades off 16 MHz speed for extreme energy efficiency. | Choose for coin-cell or energy-harvesting applications where sub-µA sleep current outweighs raw performance needs. |
Compared with STM8S903K3T3CTR, STM8S003F3P6 offers lower cost and smaller footprint but omits advanced motor control peripherals, while STM8L052C6T6 delivers superior energy efficiency at the expense of maximum clock speed and operating voltage range.
Availability
STM8S903K3T3CTR is available at Aetrix Electronics and suitable for industrial sensor nodes, BLDC motor controllers, smart meter front-ends, and home appliance UI modules requiring stable component supply across multi-year production cycles.
Supply support for STM8S903K3T3CTR 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 ICs, sensors, and analog products for industrial, automotive, and consumer markets.
The STM8S series targets cost-sensitive, reliability-critical embedded control applications - emphasizing robust I/O, integrated peripherals, and long-term supply stability for industrial automation and white goods.
FAQ
What debug interface does the STM8S903K3T3CTR support?
The STM8S903K3T3CTR uses the Single Wire Interface Module (SWIM), a proprietary ST protocol requiring only one dedicated pin (SWIM) for full in-circuit programming and real-time debugging. It replaces JTAG/SWD in STM8 architecture and is supported by ST Visual Develop (STVD) and ST-LINK/V2 tools.
Does the STM8S903K3T3CTR support hardware CRC calculation?
No, the STM8S903K3T3CTR does not include a dedicated hardware CRC peripheral. CRC computation must be implemented in firmware using standard polynomial algorithms (e.g., CRC-8 or CRC-16); no acceleration registers or dedicated instructions are provided in the STM8S903K3 data sheet.
Can the internal 16 MHz RC oscillator be calibrated for improved accuracy?
Yes, the internal 16 MHz RC oscillator is user-trimmable via the CLK_HSICALR register (address 0x50C0). Calibration adjusts frequency in ±1% steps using an 8-bit trim value; accuracy depends on VDD and temperature, with typical drift of ±2% over full operating range without trimming.
What is the maximum allowed current per I/O pin in high-sink configuration?
In high-sink mode (e.g., PA0–PA7, PB0–PB7, PC0–PC7), individual pins support up to 20 mA sink current per pin, with total package current limited to 80 mA for VDD/VSS pins. Exceeding these values risks latch-up or permanent damage per datasheet Section 10.3.6.
STM8S903K3T3CTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 32-LQFP
- 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:
- 28
- 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 7x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
STM8S903K3T3CTR FAQ
1.How can I place an order for STM8S903K3T3CTR through Aetrix?
Please submit a Request for Quotation (RFQ) for STM8S903K3T3CTR 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 STM8S903K3T3CTR reliable?
The price and inventory of STM8S903K3T3CTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM8S903K3T3CTR is usually 5 days.
3.What payment methods are accepted for STM8S903K3T3CTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM8S903K3T3CTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM8S903K3T3CTR?
STM8S903K3T3CTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM8S903K3T3CTR 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 STM8S903K3T3CTR?
For technical support, including STM8S903K3T3CTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM8S903K3T3CTR requirements.
6.How does Aetrix verify that STM8S903K3T3CTR is sourced from the original manufacturer or authorized distributors?
All STM8S903K3T3CTR 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 STM8S903K3T3CTR meets industry standards.
7.What is the process for return or replacement of STM8S903K3T3CTR?
All STM8S903K3T3CTR units undergo pre-shipment inspection (PSI). If there is an issue with STM8S903K3T3CTR, 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 STM8S903K3T3CTR part is unused and in its original packaging.
Return procedure for STM8S903K3T3CTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STM8S903K3T3CTR Tags
-
ATTINY4-TSHR
Microchip Technology
-
ATTINY10-TSHR
Microchip Technology
-
ATTINY10-TS8R
Microchip Technology
-
ATTINY202-SSNR
Microchip Technology
-
ATTINY202-SSFR
Microchip Technology
-
ATTINY402-SSNR
Microchip Technology
-
PIC16F15213T-I/MF
Microchip Technology
-
PIC16F15213-E/MF
Microchip Technology
-
PIC10F200T-I/OT
Microchip Technology
-
ATTINY412-SSNR
Microchip Technology
-
PIC10F202T-I/OT
Microchip Technology
-
ATTINY404-SSNR
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
