STMicroelectronics STM32F051K4U6

Overview

STM32F051K4U6 from STMicroelectronics is a 32-bit ARM Cortex-M0 microcontroller in UFQFPN32 (5 × 5 mm) package, featuring 16 KB Flash, 8 KB SRAM with hardware parity, 48 MHz max CPU frequency, one 12-bit ADC (1.0 µs conversion), one 12-bit DAC, and dual USART/I²C/SPI interfaces - deployed in industrial sensor nodes requiring low-power operation and integrated analog signal conditioning.

For engineers reviewing the STM32F051K4U6 datasheet, STM32F051K4U6 pinout, STM32F051K4U6 application, or STM32F051K4U6 equivalent, key selection criteria include its 32-pin UFQFPN footprint, 5 V-tolerant I/O count (up to 27), RTC with alarm/wakeup, capacitive touch sensing support (18 channels), and SWD debug interface compatibility.

Technical Context

The STM32F051K4U6 implements an ARM Cortex-M0 core with Harvard bus architecture, supporting Thumb-2 instruction set and NVIC with 32 interrupt lines. It integrates a programmable voltage detector (PVD), CRC calculation unit, and independent/system watchdog timers for robust embedded control.

Clock management includes internal 8 MHz RC oscillator (±1% over temperature), 4–32 MHz external crystal support, 32 kHz LSE for RTC calibration, and PLL for precise 48 MHz system clock derivation - enabling deterministic real-time response in motor control and metering applications.

Key Specifications

Pinout & Package

STM32F051K4U6 uses the UFQFPN32 (5 × 5 mm, 0.5 mm pitch) package, optimized for space-constrained industrial and consumer modules. Pin functions are validated per ST's DocID022265 Rev 7, Section 4 "Pinouts and pin descriptions".

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F030F4P6 and STM32F070F6P6, the STM32F051K4U6 uniquely balances analog integration (DAC + ADC + TSC), real-time capability (11 timers), and compact packaging - making it optimal for mixed-signal edge devices where size, precision, and low-power responsiveness are jointly critical.

Availability

STM32F051K4U6 is available at Aetrix Electronics and suitable for industrial sensor nodes, smart meter front-ends, capacitive touch remotes, and motor control starter kits requiring stable component supply across extended product lifecycles.

Supply support for STM32F051K4U6 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-grade components since 1987.

The STM32F0 series targets cost-sensitive, resource-constrained embedded applications demanding ARM Cortex-M0 performance, low-voltage operation (2.0–3.6 V), and rich analog/mixed-signal peripherals - especially in industrial automation and consumer IoT endpoints.

FAQ

What is the maximum operating frequency and supported voltage range for STM32F051K4U6?

The STM32F051K4U6 operates at up to 48 MHz using its internal PLL or external crystal. Its digital supply (VDD) ranges from 2.0 V to 3.6 V, while analog supply (VDDA) must be between VDD and 3.6 V, with minimum 2.4 V required for full 12-bit ADC/DAC accuracy per ST's DocID022265 Rev 7, Section 6.3.1.

Does STM32F051K4U6 support hardware CRC calculation and memory parity?

Yes - it includes a dedicated CRC calculation unit compliant with IEEE-802.3 polynomial (0x04C11DB7) and 8 KB SRAM with hardware parity checking enabled by default at reset. Parity errors trigger HardFault, ensuring data integrity in safety-aware firmware designs.

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

Up to 27 I/O pins are 5 V tolerant on the STM32F051K4U6, confirmed in Table 2 and Section 3.7 of the datasheet. This applies specifically to the UFQFPN32 package (K4U6 suffix); other variants like LQFP32 (K4T6) retain identical I/O tolerance but differ in thermal and mechanical characteristics.

Can STM32F051K4U6 drive capacitive touch sensors without external components?

Yes - its integrated Touch Sensing Controller (TSC) supports up to 18 channels with built-in charge transfer, spread-spectrum modulation, and shield electrode drive. No external RC networks or op-amps are needed for touchkey, linear slider, or rotary encoder implementations per Section 3.13 and AN4649 application note.