STMicroelectronics STM8L101K3U6

Overview

STM8L101K3U6 from STMicroelectronics is an 8-bit ultra-low-power microcontroller featuring 8 Kbytes Flash, 1.5 Kbytes RAM, and integrated peripherals including two 16-bit timers, USART, SPI, I²C, two comparators, infrared interface, and a beeper timer. It operates from 1.65 V to 3.6 V across –40 °C to +85 °C, with dynamic run current of 150 µA/MHz - optimized for battery-powered sensor nodes and portable medical devices.

For engineers reviewing the STM8L101K3U6 datasheet, STM8L101K3U6 pinout, STM8L101K3U6 application, or STM8L101K3U6 equivalent, key selection criteria include its sub-1 µA halt-mode power consumption (0.3 µA), SWIM single-wire debug interface, IR transmitter capability, and UFQFPN32 5×5 mm package with 30 I/Os - all critical for space-constrained, energy-sensitive embedded designs.

Technical Context

The STM8L101K3U6 implements the CISC-based STM8 core delivering up to 16 MIPS at 16 MHz, supported by dual internal oscillators: a 16 MHz high-speed RC (HSI) with 4 µs wakeup and a 38 kHz low-power RC (LSI) for independent watchdog and auto-wakeup unit timing. Its nested interrupt controller supports 29 external sources with software-configurable priority.

Memory architecture includes ECC-protected Flash with in-application programming, 2 Kbytes of data EEPROM, and 1.5 Kbytes of static RAM. Power management integrates three low-power modes (Wait, Active-halt, Halt), POR/PDR circuitry, and programmable I/O pull-ups - enabling rapid transition between active sensing and deep-sleep states in IoT edge nodes.

Key Specifications

Pinout & Package

STM8L101K3U6 is housed in a 32-pin UFQFPN (5 × 5 mm, 0.5 mm pitch) package with exposed thermal pad - optimized for compact PCB layouts and efficient heat dissipation in sealed enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM8L101K3U6, the STM8L051F3P6 trades IR capability and I/O count for lower cost and smaller footprint, while the EFM8LB12F32ES1 offers more memory but increases design complexity due to missing hardware IR and beeper functions - making STM8L101K3U6 optimal for IR-centric, battery-limited applications.

Availability

STM8L101K3U6 is available at Aetrix Electronics and suitable for smart metering endpoints, wearable health monitors, industrial sensor nodes, and home automation remotes requiring stable component supply and long-term production support.

Supply support for STM8L101K3U6 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, MEMS, and automotive semiconductors.

The STM8L101 series belongs to ST's ultra-low-power 8-bit MCU product line, engineered specifically for energy-harvesting and battery-operated applications where sub-microamp standby current and minimal external components are mandatory.

FAQ

Does STM8L101K3U6 support in-circuit programming after soldering?

Yes. The device features a hardware Single Wire Interface Module (SWIM) that enables full in-circuit programming and non-intrusive debugging via a single pin (SWIM), even after PCB assembly. No bootloader code is required, and ST-LINK/V2-1 or compatible debuggers can reprogram Flash and EEPROM without removing the chip.

What is the maximum operating frequency and how is it achieved?

The STM8L101K3U6 achieves up to 16 MHz CPU frequency using its internal 16 MHz high-speed RC oscillator (HSI), which requires no external crystal or resonator. This oscillator provides typical accuracy of ±1% over voltage and temperature, enabling reliable high-speed operation while maintaining ultra-low-power characteristics.

Can PA0 drive standard infrared LEDs directly?

Yes. PA0 is configured as a high-sink LED/IR driver capable of sinking up to 20 mA continuously, allowing direct connection to common 5 mm or SMD infrared LEDs (e.g., Vishay TSAL6100) without external transistors. The IR peripheral handles carrier generation and modulation automatically.

Is there hardware support for real-time clock (RTC) functionality?

No. The STM8L101K3U6 does not integrate a dedicated RTC peripheral. However, the Auto-Wakeup Unit (AWU) driven by the 38 kHz LSI oscillator can generate periodic interrupts at intervals from 122 µs to ~16 s, enabling software-based RTC emulation with sub-second resolution and ultra-low-power background timing.