STM8S903K3U6 - 16MHz 8-Bit MCU with 8KB Flash | ST
MPN： STM8S903K3U6 ✓ 啟用中STM8S903K3U6 概覽
An 8-bit microcontroller is a compact embedded-processing component designed around a simple central processing unit, program memory, working memory, and integrated peripherals. The STM8S family belongs to the broader hierarchy of microcontrollers, embedded processors, and semiconductors. Its combination of integrated Flash, true EEPROM, analog conversion, and serial interfaces makes it useful for cost-sensitive appliance control, industrial sensing, compact instrumentation, and low-to-moderate-speed communication equipment.
Key features include 8 KB of Flash program memory, 1 KB of RAM, and 640 bytes of integrated true data EEPROM. The device supports a 16 MHz maximum clock and includes a 10-bit analog-to-digital converter, two timers, one UART, SPI, and I2C. Its operating voltage of 2.95 V to 5.5 V supports both 3.3 V and 5 V systems, while a temperature range of -40°C to +85°C covers common industrial and commercial environments.
The STM8S903K3/F3 access-line architecture emphasizes performance, robustness, and reduced system cost. Flash permits in-system program storage, true EEPROM retains calibration or configuration data without external memory, and the ADC provides an economical path for analog measurement. The 32-pin UFQFPN package also offers fine-pitch external connectivity for sensors, actuators, displays, and communication transceivers, although its 0.5 mm pitch requires careful PCB assembly and inspection.
Typical applications include sensor nodes, appliance controllers, compact industrial interfaces, low-speed data loggers, and embedded modules requiring UART, SPI, or I2C connectivity. Designers can connect analog inputs to the 10-bit ADC, use the timers for periodic measurement or output generation, and retain operating parameters in EEPROM. A UART bridge or level translator can extend the device into RS-232 or RS-485 systems.
The primary design consideration is PCB implementation. A 32-pin UFQFPN package requires a land pattern capable of 0.5 mm pitch routing, adequate solder paste coverage, and careful control of thermal and electrical conditions. Firmware should also verify the device-specific reset behavior, clock configuration, peripheral mapping, and ADC calibration sequence against the manufacturer documentation before production.
This page consolidates verified manufacturer specifications, distributor availability, procurement information, interface guidance, and same-footprint replacement analysis. It is intended to provide engineering context beyond a basic distributor listing while clearly identifying data that requires confirmation from the manufacturer datasheet.
直接替換替代品，適用於 STM8S903K3U6 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
STM8S903K3U6TR
✅ 直接替換📋 參考替代品（不在目錄中）
STM8S903K3U6 最大額定值與電氣特性
| Product Type | 8-bit microcontroller |
| 最大時脈頻率 | 16 MHz |
| Flash Program Memory | 8 KB |
| RAM | 1 KB |
| True Data EEPROM | 640 bytes |
| ADC Resolution | 10 bits |
| Timer Count | 2 |
| Serial Interfaces | UART, SPI, and I2C |
| I/O Port Count | 16 |
| Supply Voltage Range | 2.95 V to 5.5 V |
| 工作溫度範圍 | -40°C to +85°C |
| 封裝 | 32-pin UFQFPN, 5 x 5 mm |
| Package Pitch | 0.5 mm |
| Architecture | 8-bit STM8S |
| Memory Organization | 8K x 8 Flash |
| RoHS 狀態 | Compliant |
| Lifecycle Stage | Active |
| Program Memory Type | Flash |
| Data Memory Type | True data EEPROM |
| 安裝類型 | Surface mount |
| Manufacturer Product Family | STM8S903K3/F3 access line |
STM8S903K3U6 0.5 mm 腳位配置指南
STM8S903K3U6（0.5 mm 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： STM8S903K3U6.
請參閱 資料表 以查看完整腳位配置。
典型應用
STM8S903K3U6 適用於 6 應用s: Compact Industrial Sensor Node, Appliance Control Panel, Low-Speed Data Logger, UART-to-I2C Sensor Gateway, Cost-Sensitive Embedded Control, Small Communication Interface Module.
Compact Industrial Sensor Node
The STM8S903K3U6 fits compact sensor nodes that must acquire analog measurements and forward readings over a short serial link. Its 10-bit ADC handles sensors with moderate resolution requirements, while 16 MHz operation supports responsive sampling and control tasks. The 1 KB RAM and 8 KB Flash provide space for acquisition logic, filtering, diagnostics, and communication routines without an external microcontroller. The 640-byte true EEPROM can retain calibration factors or configuration values across power cycles. Designers should budget I/O pins for the sensor interface and keep analog routing away from switching nodes to preserve useful signal integrity.
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Appliance Control Panel
The STM8S903K3U6 is appropriate for appliance control panels that combine button or sensor inputs, status indication, and a low-speed communications link. Two timers support periodic control and timing functions, while UART, SPI, or I2C can connect a display, keypad, EEPROM, or external controller. Its 8 KB Flash is best suited to a focused control application rather than a feature-rich graphical interface. EEPROM provides a compact place to store user settings or calibration data. Because the device has only 16 I/O ports, designers should perform a pin-budget review early and account for debug, reset, and shared peripheral connections.
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Low-Speed Data Logger
The STM8S903K3U6 can serve as the control element in a low-speed data logger built around periodic sensor sampling and removable or nonvolatile data storage. The 10-bit ADC supports analog channels, the timers establish sampling intervals, and SPI or I2C can connect serial storage or an external memory device. True EEPROM is useful for counters, sequence numbers, and configuration rather than bulk logging because only 640 bytes are available. Firmware should use a wear-aware update strategy and preserve write endurance. If the logger must retain large event buffers between power cycles, an external FRAM or flash device is preferable to stretching the internal EEPROM.
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UART-to-I2C Sensor Gateway
The STM8S903K3U6 is suitable for a gateway that accepts data through UART and distributes commands or measurements through I2C or SPI. Its three serial-interface types allow the same controller to support an upstream host and one or more downstream sensors. The 16 MHz clock and 1 KB RAM are appropriate for short frames and protocol conversion rather than high-throughput buffering. A typical design includes frame validation, timeout handling, address management, and status reporting. The 640-byte EEPROM can store gateway settings, while the 10-bit ADC can support an analog health input if the I/O allocation permits.
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Cost-Sensitive Embedded Control
The STM8S903K3U6 supports cost-sensitive embedded-control products where integrated Flash, EEPROM, ADC, timers, and serial interfaces can replace several discrete components. At a verified starting price of $0.7299 as of 2026-10-30, it is relevant to volume designs, but total system cost must include the 0.5 mm pitch UFQFPN assembly process. The 8 KB Flash and 1 KB RAM impose a clear firmware budget, favoring compact code and selective use of buffers. A disciplined hardware partition can preserve manufacturability by moving high-speed or high-pin-count functions to dedicated devices while retaining the MCU for control logic.
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Small Communication Interface Module
The STM8S903K3U6 fits a compact communication-interface module that exposes UART, SPI, or I2C to a larger control system. Its true EEPROM can retain configuration such as device addresses and operating modes, while the ADC can supervise an analog supply or signal condition. The 5 x 5 mm UFQFPN package helps minimize board area, although fine-pitch assembly and test access require careful planning. External transceivers should be selected to match the actual line standard and voltage levels. Firmware should include framing, timeout, reset, and bus-recovery behavior so a downstream controller can reinitialize the module predictably.
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推薦產品摘要
工程參考資料，適用於 STM8S903K3U6 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | STM8S903K3U6TR |
|---|---|---|
| Package | 32-pin UFQFPN, 5 x 5 mm | 32-pin UFQFPN, 5 x 5 mm - same |
| Brand | STMicroelectronics | STMicroelectronics |
| Maximum Clock Frequency | 16 MHz | 16 MHz |
| Flash Program Memory | 8 KB | 8 KB |
| RAM | 1 KB | 1 KB |
| True Data EEPROM | 640 bytes | 640 bytes |
| ADC Resolution | 10 bits | 10 bits |
| Supply Voltage Range | 2.95 V to 5.5 V | 2.95 V to 5.5 V |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C |
| Shipping Format Difference | Non-TR ordering option | Tape-and-reel ordering option |
主要差異化特點
- Integrated retained data memory (對比STM8S903K3U6TR)
- Compact analog and serial integration (對比STM8S903K3U6TR)
- Production-oriented shipment option (對比STM8S903K3U6)
設計說明
Design the PCB around the manufacturer's recommended 32-pin UFQFPN land pattern for a 0.5 mm pitch, 5 x 5 mm package. Place the device close to the points where its pins are used, keep analog inputs away from high-current switching paths, and provide uninterrupted ground references. The fine pitch increases assembly and inspection difficulty, so paste volume, stencil aperture design, reflow profile, and board tolerances should be validated using the manufacturer's package guidance and normal production checks.
Supply the STM8S903K3U6 within its verified 2.95 V to 5.5 V operating range and ensure every connected peripheral shares a compatible logic level. Place local bypass capacitance close to the supply pins and keep return-current paths short. If the MCU controls relays, motors, lamps, or other inductive loads, use separate drive circuitry and transient protection rather than routing load current through MCU pins. Validate startup, reset, and brownout behavior across the complete power-supply tolerance range.
Treat analog and communication signals according to their actual bandwidth rather than the 16 MHz CPU clock. Keep ADC traces short, provide a suitable analog ground strategy, and isolate sensitive input routing from switching nodes and high-current outputs. For I2C, use pull-up values appropriate to bus capacitance and voltage level; for SPI and UART, account for trace length, impedance, grounding, and peripheral timing. Grounding the unused communications pins and validating pin multiplexing in firmware also prevents accidental alternate-function conflicts.
Do not base a production design on the abbreviated distributor specifications alone. The verified STM8S903K3U6 provides only 1 KB of RAM and 8 KB of Flash, so firmware size, stack depth, interrupt usage, and DMA or buffer assumptions must be checked. Verify the ADC conversion sequence, timer channels, UART configuration, I2C behavior, and reset cause handling in the manufacturer documentation. Also confirm the exact packing suffix and order code because STM8S903K3U6TR uses a different shipment presentation from the non-TR part.
合規資訊
The verified component listing identifies the STM8S903K3U6 as RoHS compliant. The supplied data does not separately establish REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is not applicable because this is a general-purpose microcontroller rather than an automotive-qualified part identified in the verified data.