STM8S903K3U3 - 16MHz 8-Bit MCU with 8KB Flash | STMicroelectronics
MPN： STM8S903K3U3 ✓ 啟用中STM8S903K3U3 概覽
An 8-bit microcontroller is a compact embedded-computing device that executes programmed instructions, reads inputs, controls outputs, and manages communication interfaces. Within the semiconductor hierarchy, the STM8S903K3U3 belongs to the STM8S family, the STM8 access line, the broader 8-bit microcontroller class, and the wider embedded-processing and power-management ecosystem. Its combination of mixed signal and serial connectivity makes it suitable for compact control systems rather than high-compute applications.
The device provides 8 Kbyte of Flash for program storage, 1 Kbyte of RAM for working memory, and 640 bytes of true data EEPROM for parameters that must retain their values. The 10-bit ADC supports analog-to-digital measurements, while two timers support timing, periodic events, and basic input-capture or output-compare functions. UART, SPI, and I2C interfaces enable connection to sensors, displays, transceivers, memory devices, and other embedded peripherals.
The operating supply range is 2.95 V to 5.5 V, supporting both 3.3 V and 5 V system architectures. Its 16 MHz maximum clock provides adequate execution bandwidth for control loops, protocol handling, and sequential logic. The device exposes 16 I/O ports and is offered in a compact 32-pin no-lead package with a 0.65 mm pitch, reducing board area while retaining a substantial pin count for mixed-signal and serial-interface designs.
Typical applications include industrial sensor nodes, compact motor controllers, digital control panels, appliance interfaces, LED-control boards, and low-cost serial bridges. The STM8S903K3U3 is particularly useful where a design needs local analog measurement, nonvolatile configuration storage, and multiple serial buses without adopting a higher-pin-count or higher-cost microcontroller.
PCB design should place the decoupling capacitor adjacent to the supply pins and route analog, digital, and clock signals with appropriate separation. Confirm the exact exposed-pad, ground, reset, clock, and I/O assignments from the manufacturer pinout and layout guidance before fabrication.
This product page combines the manufacturer’s device information with a practical feature summary, application guidance, verified specifications, sourcing information, and a conservative replacement assessment that distinguishes true pin-compatible choices from merely similar devices.
直接替換替代品，適用於 STM8S903K3U3 — 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。
此系列的變體
與下列產品可直接替換的同系列型號： STM8S903K3U3 （相同外形與佔位） — 差異在於 Package.
STM8S903K3T6
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →STM8S903F3U3TR
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
STM8S903K3U3 最大額定值與電氣特性
| Product Type | 8-bit microcontroller |
| Product Family | STM8S access line |
| Maximum Clock Speed | 16 MHz |
| Flash Program Memory | 8 Kbyte |
| RAM | 1 Kbyte |
| True Data EEPROM | 640 bytes |
| ADC Resolution | 10-bit |
| Timer Count | 2 timers |
| Serial Interfaces | UART, SPI, and I2C |
| Supply Voltage Range | 2.95 V to 5.5 V |
| I/O Port Count | 16 |
| 封裝 | 32-pin UFQFPN |
| Package Dimensions | 5 x 5 mm |
| Package Pitch | 0.65 mm |
| 安裝類型 | Surface mount |
| Lead-Free Status | RoHS compliant |
| 生命週期狀態 | Active |
STM8S903K3U3 0.65 mm 腳位配置指南
STM8S903K3U3（0.65 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： STM8S903K3U3.
請參閱 資料表 以查看完整腳位配置。
典型應用
STM8S903K3U3 適用於 6 應用s: Industrial Sensor Node, Compact Motor Control, Digital Appliance Controller, Serial Protocol Bridge, LED Lighting Controller, Security and Access Control Module.
Industrial Sensor Node
The STM8S903K3U3 fits a compact industrial sensor node because its 16 MHz processing rate, 10-bit ADC, and 16 I/O ports support periodic analog measurements and discrete control functions without requiring a high-compute MCU. The 2.95 V to 5.5 V supply range supports common industrial rails, while I2C and SPI provide flexible links to sensors, converters, and memory devices. Its 8 Kbyte Flash, 1 Kbyte RAM, and 640-byte true EEPROM allow compact firmware, working state, and retained configuration to coexist. Design the board around the 32-pin UFQFPN footprint, place the supply capacitor close to the device, and validate analog grounding and serial-bus signal integrity before deployment.
推薦
Compact Motor Control
The STM8S903K3U3 is appropriate for a compact motor-control board where an 8-bit MCU must combine timing functions, digital inputs, and serial configuration. Its two timers can support periodic control and timing functions, while the 10-bit ADC can monitor analog feedback such as a potentiometer or sensor output. The 32-pin UFQFPN package preserves access to UART, SPI, I2C, and 16 I/O ports in a small board area. The 2.95 V to 5.5 V operating range allows use with common 3.3 V or 5 V power systems. Confirm timer routing, motor-drive interface levels, thermal margins, and protective shutdown behavior during hardware validation.
推薦
Digital Appliance Controller
The STM8S903K3U3 suits digital appliance controllers that require several interfaces, retained settings, and modest real-time control. The 10-bit ADC can supervise an analog panel input, two timers can organize periodic control functions, and UART, SPI, and I2C can connect to display modules, sensors, and external memory. True data EEPROM provides 640 bytes for configuration values that must survive power loss, while the 1 Kbyte RAM handles temporary operating data. Its 16 MHz clock is appropriate for embedded control logic rather than graphics-intensive workloads. The 5 x 5 mm UFQFPN package helps reduce appliance PCB area, but careful decoupling, exposed-pad soldering, and EMI control remain essential.
推薦
Serial Protocol Bridge
The STM8S903K3U3 can implement a compact serial bridge because it includes UART, SPI, and I2C interfaces alongside 16 general-purpose I/O ports. A design can translate between an external host UART and a sensor or memory device reached through SPI or I2C, while timers provide periodic status or timeout handling. Its 8 Kbyte Flash is sufficient for focused protocol conversion firmware, and 1 Kbyte RAM supports packet staging and interface state. Operating from 2.95 V to 5.5 V simplifies integration with mixed-voltage peripherals when level translation is implemented correctly. Validate protocol timing, pull-up requirements, bus capacitance, and reset behavior against the final system requirements.
推薦
LED Lighting Controller
The STM8S903K3U3 is well suited to LED lighting control because two timers support periodic timing functions while UART, SPI, or I2C connects the controller to LED drivers, color sensors, or configuration modules. The 10-bit ADC can monitor an analog light-level or adjustment input, and the 640-byte true EEPROM can retain setup values. A 16 MHz clock provides sufficient throughput for sequencing and communication without adding a higher-cost processor. The 32-pin UFQFPN package allows a compact controller board, while the 2.95 V to 5.5 V range supports common supply architectures. Keep high-current LED paths separate from sensitive control traces and verify driver interface voltage levels before connecting external modules.
推薦
Security and Access Control Module
The STM8S903K3U3 can serve as the control element in a compact access-control module where local I/O, serial communication, and retained configuration are more important than high processing throughput. Its 16 I/O ports can support status inputs, indicators, and alarm signaling, while UART or I2C can connect to a reader, keypad, or host controller. The 10-bit ADC supports supervisory measurements, and 640 bytes of true EEPROM are useful for device-specific settings. The 2.95 V to 5.5 V range accommodates common embedded rails, and the active lifecycle status supports long-term product planning. Validate electrical surge levels, debounce behavior, safe-state outputs, and firmware update mechanisms for the completed security enclosure.
推薦
推薦產品摘要
工程參考資料，適用於 STM8S903K3U3 — 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 | STM8S903K3T6 | STM8S903F3U3TR |
|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Package | 32-pin UFQFPN (5 x 5 mm) | 32-pin UFQFPN (5 x 5 mm) | 32-pin UFQFPN (5 x 5 mm) |
| Product Family | STM8S903K3 access line | STM8S903K3 access line | STM8S903F3 access line |
| Maximum Clock Speed | 16 MHz | 16 MHz | 16 MHz |
| ADC Resolution | 10-bit | 10-bit | 10-bit |
| Timer Count | 2 timers | 2 timers | 2 timers |
| Serial Interfaces | UART, SPI, and I2C | UART, SPI, and I2C | UART, SPI, and I2C |
| I/O Port Count | 16 | 16 | 16 |
主要差異化特點
- Exact STM8S903K3 memory and peripheral configuration (對比STM8S903F3U3TR)
- Direct family ordering alternative (對比STM8S903K3T6)
- Mixed-signal and serial interface integration (對比STM8S903K3T6)
設計說明
Place the device-side supply capacitor directly beside the power and ground terminals, and provide a short, low-inductance return path from the exposed pad according to the manufacturer package guidance. The UFQFPN package has a 0.65 mm pitch, so trace spacing and paste coverage should be checked against the land pattern before release. Keep sensitive analog inputs away from switching nodes and high-current return paths.
Operate the STM8S903K3U3 only within its stated 2.95 V to 5.5 V supply range. Because the device supports both 3.3 V and 5 V systems, confirm that every connected peripheral uses a compatible logic level or has suitable level translation. Review the datasheet’s reset, clock, and pin-state requirements before applying power so that no external peripheral can back-power an I/O during startup.
Use the manufacturer pin-description table and package drawing when assigning tracks; do not rely on a generic 32-pin QFN diagram. Verify oscillator connections, reset behavior, UART, SPI, I2C, ADC inputs, and the exposed pad. Keep I2C pull-up placement close to the bus endpoints and maintain controlled return paths for serial signals to reduce susceptibility to switching noise and ground bounce.
Do not assume that every STM8S903 ordering code is a production drop-in replacement. Memory capacity, package suffix, temperature grade, exposed-pad implementation, and lifecycle conditions can differ even when the family and package name appear similar. For STM8S903K3U3 substitutions, compare the exact terminal map and ordering information, then rerun boot, timing, ADC, and peripheral tests before approving the change.
合規資訊
The product listing identifies the device as RoHS compliant. No definitive REACH, AEC-Q100, halogen-free, or conflict-minerals declaration was identified, so those fields remain unknown.