STMicroelectronics STM8S103F3U6TR

Overview

STM8S103F3U6TR from STMicroelectronics is an 8-bit access-line microcontroller featuring a 16 MHz STM8 core, 8 Kbyte Flash program memory, 640 byte data EEPROM, 10-bit ADC with 5 channels, three timers (including advanced control timer TIM1), and UART/SPI/I²C interfaces. It operates from 2.95–5.5 V and targets cost-sensitive embedded control in industrial sensors, motor drives, and smart home peripherals.

For engineers reviewing the STM8S103F3U6TR datasheet, STM8S103F3U6TR pinout, STM8S103F3U6TR application, or STM8S103F3U6TR equivalent, key selection criteria include its 20-pin UFQFPN package, 16 MHz max CPU frequency at 3.3 V/5 V, integrated 128 kHz low-power RC oscillator, 300 kcycle EEPROM endurance, and SWIM single-wire debug interface compatibility.

Technical Context

The STM8S103F3U6TR implements a Harvard-architecture 8-bit core with 3-stage pipeline and extended instruction set, enabling deterministic real-time execution. Its clock system integrates four independent sources-external crystal, external clock input, user-trimmable 16 MHz RC, and factory-calibrated 128 kHz RC-with clock security monitoring and flexible peripheral gating.

Interrupt handling uses a nested controller supporting 32 vectors and up to 27 external interrupts across six priority levels. Memory subsystem includes 8 Kbyte Flash with 20-year data retention at 55 °C after 10 kcycles, 640 byte true EEPROM (300 kcycle endurance), and 1 Kbyte RAM-all mapped into unified address space with hardware protection options.

Key Specifications

Pinout & Package

STM8S103F3U6TR is housed in a 20-lead UFQFPN (3 × 3 mm, 0.5 mm pitch) package with exposed thermal pad. Pin functions are validated per STMicroelectronics DS6120 Rev 15 Section 5.2.2 and Table 6.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with STM8S103F3U6TR, STM8S003F3P6 trades EEPROM capacity and advanced timer capability for lower unit cost, while EFM8BB10F8G-A-QFN20 offers different ecosystem trade-offs but lacks the integrated low-power timing and nonvolatile data storage architecture critical for maintenance-free embedded nodes.

Availability

STM8S103F3U6TR is available at Aetrix Electronics and suitable for industrial sensor nodes, smart thermostat controllers, brushless DC motor starters, and POS peripheral interfaces requiring stable component supply over multi-year production cycles.

Supply support for STM8S103F3U6TR 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 discrete components for industrial, automotive, and consumer markets.

The STM8S series delivers cost-optimized 8-bit MCUs targeting resource-constrained embedded systems where reliability, low power, and debug simplicity outweigh raw processing throughput - especially in white goods, building automation, and motor control.

FAQ

Does STM8S103F3U6TR support in-circuit debugging via SWIM?

Yes. The STM8S103F3U6TR integrates ST's Single-Wire Interface Module (SWIM), enabling full-speed debugging, flash programming, and memory inspection using only one dedicated pin (SWIM) and ground. No additional debug headers or level shifters are required, and ST-LINK/V2 or compatible programmers provide full IDE integration via STM8CubeIDE.

What is the maximum operating frequency at 3.3 V supply?

The STM8S103F3U6TR achieves a guaranteed maximum CPU frequency of 16 MHz at 3.3 V, as specified in Section 10.3.1 of DS6120 Rev 15. This is enabled by its internal 16 MHz RC oscillator, which is factory-trimmed and user-adjustable via calibration register (CLK_HSICALR) to maintain timing accuracy across voltage and temperature.

Can the 10-bit ADC operate with external reference voltage?

No. The ADC uses an internal reference derived from VDD and has no provision for external reference input. Its full-scale range is fixed to VDD, with typical INL/DNL of ±1 LSB and effective resolution maintained across 2.95–5.5 V supply range - verified in Table 45 and Figure 21 of the datasheet.

Is the UFQFPN20 package RoHS-compliant and lead-free?

Yes. The STM8S103F3U6TR in UFQFPN20 packaging meets RoHS Directive 2011/65/EU and is fully lead-free, with matte tin finish on terminals. Package mechanical data in Table 54 (DS6120 Rev 15) confirms compliance with JEDEC MO-220 specifications and IPC-7351B land pattern recommendations.