STMicroelectronics STM32F051K4U7TR

Overview

STM32F051K4U7TR from STMicroelectronics is an ARM® Cortex®-M0 32-bit microcontroller with 16 KB Flash, 8 KB SRAM, 48 MHz max CPU frequency, and integrated peripherals including a 12-bit ADC, single-channel 12-bit DAC, two analog comparators, and up to 39 GPIOs - used in industrial sensor nodes requiring low-power operation and capacitive touch sensing.

For engineers reviewing the STM32F051K4U7TR datasheet, STM32F051K4U7TR pinout, STM32F051K4U7TR application, or STM32F051K4U7TR equivalent, key selection criteria include Flash/SRAM size, 5 V-tolerant I/O count (up to 36), RTC with alarm, and support for USB-less HID-class human interface devices via capacitive sensing and USART/LIN.

Technical Context

This MCU implements a single-cycle 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), hardware CRC unit, and memory protection unit (MPU) for secure boot and runtime integrity checks.

Clock management includes dual oscillators: 4–32 MHz HSE for precision timing and 32 kHz LSE for RTC, plus internal RC sources (8 MHz HSI, 40 kHz LSI) with PLL for system clock scaling. Power control supports Sleep, Stop, and Standby modes with wake-up from GPIO, RTC alarm, or USART activity.

Key Specifications

Pinout & Package

STM32F051K4U7TR uses the UFQFPN32 (5 × 5 mm, 0.5 mm pitch) package with 32-pin layout optimized for compact industrial and consumer control modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F030F4P6 and STM32F070F6P6, the STM32F051K4U7TR uniquely combines capacitive touch sensing, DAC, and 5 V-tolerant I/O in a 32-pin package - making it optimal for space-constrained, analog-rich human interface and sensor edge nodes where USB is unnecessary.

Availability

STM32F051K4U7TR is available at Aetrix Electronics and suitable for industrial sensor nodes, smart thermostat HMIs, USB-free HID peripherals, and motor control actuators requiring stable component supply across long-lifecycle deployments.

Supply support for STM32F051K4U7TR 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, specializing in microcontrollers, power management, and automotive-grade ICs with strong industrial and consumer focus.

The STM32F0 series targets cost-sensitive, low-power embedded applications requiring rich analog integration and touch capability - designed specifically for sensor edge nodes, appliance controls, and human interface devices.

FAQ

What is the maximum operating frequency and supported voltage range?

The STM32F051K4U7TR operates at up to 48 MHz with a digital supply voltage (VDD) range of 2.0–3.6 V and analog supply (VDDA) from 2.4–3.6 V. Its internal 8 MHz RC oscillator can be multiplied by the PLL to achieve full-speed operation without external crystal, though HSE support enables higher timing precision for RTC or communication timing-critical functions.

Does this MCU support hardware capacitive touch sensing?

Yes - it integrates a dedicated Touch Sensing Controller (TSC) supporting up to 18 capacitive sensing channels for touchkey, linear, and rotary sensors. The TSC includes built-in charge transfer, synchronization, and noise filtering, enabling robust touch detection without external components or software-intensive polling algorithms.

What debug interface does STM32F051K4U7TR use?

It uses Serial Wire Debug (SWD) with two dedicated pins: SWDIO (bidirectional data) and SWCLK (clock). This 2-pin interface supports full JTAG-equivalent functionality - including flash programming, real-time register inspection, and hardware breakpoints - and is compatible with ST-LINK/V2 and other ARM-compliant debug probes.

How many I/O pins are 5 V tolerant, and what is their safe operating margin?

Up to 36 GPIOs are 5 V tolerant, meaning they safely accept input voltages up to 5.5 V regardless of VDD level (2.0–3.6 V). This tolerance is guaranteed across the full industrial temperature range (–40°C to +85°C) and allows direct interfacing with 5 V logic, sensors, or legacy peripherals without external level-shifting circuitry.