STMicroelectronics STM32F051K6U6

Overview

STM32F051K6U6 from STMicroelectronics is a 32-bit ARM® Cortex®-M0 microcontroller in UFQFPN32 (5 × 5 mm) package, featuring 32 KB Flash, 8 KB SRAM with hardware parity, and operating at up to 48 MHz. It integrates one 12-bit ADC (1.0 µs conversion), one 12-bit DAC, two analog comparators, 18 capacitive sensing channels, and communication interfaces including two USARTs (one with LIN/IrDA), two I²C (one Fast Mode Plus), and two SPI (18 Mbit/s). It targets cost-sensitive industrial control and smart sensor nodes requiring low-power operation and touch interface capability.

For engineers reviewing the STM32F051K6U6 datasheet, STM32F051K6U6 pinout, STM32F051K6U6 application, or STM32F051K6U6 equivalent, key selection criteria include Flash/SRAM size, 5 V-tolerant I/O count (up to 36), real-time clock with alarm, SWD debug support, and integrated capacitive touch sensing-critical for embedded HMI and battery-powered edge devices.

Technical Context

The STM32F051K6U6 implements an ARM Cortex-M0 core with Harvard architecture, supporting Thumb-2 instruction set and nested vectored interrupt controller (NVIC) with up to 32 interrupts. Its memory subsystem includes 32 KB of single-cycle Flash with prefetch buffer and 8 KB of SRAM with hardware parity checking for safety-critical data retention.

Clock management combines multiple sources: 4–32 MHz external crystal, 32 kHz RTC oscillator, internal 8 MHz RC (with x6 PLL), and 40 kHz LSI. Power management supports Sleep, Stop, and Standby modes with programmable voltage detector (PVD), POR/PDR, and VBAT backup for RTC and registers-enabling sub-µA standby current with RTC active.

Key Specifications

Pinout & Package

STM32F051K6U6 uses the UFQFPN32 (5 × 5 mm, 0.5 mm pitch) package with 32 pins and exposed thermal pad. This compact, lead-free ECOPACK®2-compliant package supports high-density PCB layouts and efficient thermal dissipation in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F030F4P6 and STM32F070F6P6, the STM32F051K6U6 uniquely balances Flash capacity, analog precision (12-bit ADC/DAC), and human-interface capability (18-channel TSC) in a 5 × 5 mm package-making it optimal for space-constrained, sensor-rich edge nodes where mixed-signal integration reduces board area and component count.

Availability

STM32F051K6U6 is available at Aetrix Electronics and suitable for industrial sensor nodes, smart home HMI panels, PLC I/O modules, and portable medical diagnostics requiring stable component supply across multi-year production cycles.

Supply support for STM32F051K6U6 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 automotive semiconductors since 1987.

The STM32F0 series targets cost-sensitive, energy-efficient embedded applications requiring ARM Cortex-M0 performance with rich analog and timing peripherals-optimized for industrial control, appliance HMI, and IoT edge nodes.

FAQ

What is the maximum operating frequency and supported voltage range for STM32F051K6U6?

The STM32F051K6U6 operates at up to 48 MHz using its internal 8 MHz RC oscillator with PLL or external crystal. Its digital supply (VDD) ranges from 2.0 V to 3.6 V, while analog supply (VDDA) must be between 2.4 V and 3.6 V and may equal VDD. These specifications are validated per ST's DocID022265 Rev 7 electrical characteristics tables (Sections 6.3.1 and 6.3.6).

Does STM32F051K6U6 support in-circuit debugging and programming?

Yes, it supports Serial Wire Debug (SWD) via dedicated SWDIO and SWCLK pins, enabling full JTAG-style debugging, flash programming, and real-time variable inspection using standard tools like ST-LINK/V2. No external debugger hardware is required beyond a 2-pin SWD interface, and no bootloader activation is needed for standard flash writes.

How many I/O pins are 5 V tolerant, and which packages support them?

Up to 36 I/O pins are 5 V tolerant across all STM32F051xx variants, including the K6U6 in UFQFPN32. This tolerance applies to all GPIOs except those dedicated to analog functions (e.g., ADC inputs, VREF+), and is specified in Section 6.3.14 of the datasheet. The UFQFPN32 package exposes 29 usable GPIOs, all 5 V tolerant unless configured as analog inputs.

What peripheral resources enable capacitive touch sensing on this MCU?

The STM32F051K6U6 integrates a dedicated Touch Sensing Controller (TSC) supporting up to 18 capacitive sensing channels using charge-transfer measurement. It requires no external components beyond PCB electrodes and supports touchkey, linear, and rotary sensor topologies. Calibration and noise filtering are handled in hardware, and driver libraries are provided in STM32CubeF0.