STMicroelectronics STM32F031K6U6

Overview

STM32F031K6U6 from STMicroelectronics is a 32-bit ARM® Cortex®-M0 microcontroller in UFQFPN32 (5 × 5 mm) package, operating up to 48 MHz with 32 KB Flash, 4 KB SRAM (HW parity), and integrated 12-bit ADC (1.0 µs conversion), advanced timer (TIM1 with deadtime & emergency stop), and multiple communication interfaces (I²C Fast Mode Plus, USART with IrDA/LIN, SPI at 18 Mbit/s). It targets cost-sensitive industrial control and smart sensor nodes requiring low-power operation and robust analog integration.

For engineers reviewing the STM32F031K6U6 datasheet, STM32F031K6U6 pinout, STM32F031K6U6 application, or STM32F031K6U6 equivalent, key selection criteria include its 32-pin UFQFPN footprint, 5 V-tolerant I/O count (up to 26 pins), RTC with alarm/wakeup from Stop/Standby, programmable voltage detector (PVD), and extended temperature range (–40 to +105°C).

Technical Context

The STM32F031K6U6 implements an ARM Cortex-M0 core with Harvard architecture, supporting Thumb-2 instruction set and NVIC for deterministic interrupt handling. Its clock system integrates four oscillators: 4–32 MHz HSE, 32 kHz LSE for RTC, 8 MHz HSI with x6 PLL, and 40 kHz LSI - enabling flexible low-power mode transitions and precise timing control across sleep, stop, and standby states.

Peripheral interconnect uses AHB/APB buses with DMA support for ADC, USART, SPI, and I²C. The 12-bit ADC features separate analog supply (2.4–3.6 V), internal reference (VREFINT), and temperature sensor calibration. TIM1 provides six-channel PWM with hardware deadtime insertion and emergency input, critical for motor gate drive safety compliance.

Key Specifications

Pinout & Package

STM32F031K6U6 is housed in a 32-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN32) package measuring 5 × 5 × 0.55 mm, with 0.5 mm pitch and exposed thermal pad for enhanced thermal dissipation in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F031K6U6, STM32F030K6T6 reduces memory reliability and peripheral sophistication for lower BOM cost, while STM32F042K6U6 adds USB at no package or pin-count penalty - making it ideal for field-upgradable embedded devices.

Availability

STM32F031K6U6 is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, energy metering interfaces, and home appliance control panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM32F031K6U6 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 analog components for industrial, automotive, and consumer markets.

The STM32F0 series targets cost-optimized, low-power embedded applications with Cortex-M0 cores, emphasizing analog integration, robust I/O, and simplified toolchain adoption for entry-level firmware development.

FAQ

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

The STM32F031K6U6 achieves 48 MHz maximum CPU frequency using its internal 8 MHz HSI oscillator with a 6× PLL multiplier, or optionally via an external 4–32 MHz crystal (HSE). The PLL output feeds the system clock (SYSCLK), and all APB/AHB peripherals derive clocks from this source with configurable prescalers. This configuration is validated across the full –40 to +105°C temperature range.

Does the device support true 5 V-tolerant I/O on all pins?

No - only up to 26 GPIOs (PA0–PA15, PB0–PB1, and specific alternate function pins) are specified as 5 V tolerant in the datasheet. Pins such as VDDA, NRST, BOOT0, and SWDIO are not 5 V tolerant and must remain within their absolute maximum ratings (≤3.6 V for most inputs). Always consult Table 11 (Pin Definitions) and Section 6.3.14 (I/O port characteristics) for per-pin voltage limits.

How does the RTC maintain time during power loss?

The RTC retains timekeeping and alarm functionality during main power loss by switching to the VBAT supply (1.65–3.6 V), which powers the RTC oscillator, calendar registers, and backup SRAM. A coin-cell battery or supercapacitor connected to VBAT ensures continuous operation. The LSE (32.768 kHz) crystal remains active in Standby mode, and wakeup from Stop/Standby occurs in under 5 µs upon RTC alarm event.

Is the 12-bit ADC fully differential or single-ended?

The ADC is single-ended only, with 10 input channels selectable via analog multiplexer. It supports conversion against VREFINT (1.22 V) or external VDDA (2.4–3.6 V) as reference. Differential mode is not implemented - no dedicated IN+ and IN– pairs exist. However, software can emulate pseudo-differential measurements using two consecutive single-ended reads and subtraction, though without common-mode rejection or guaranteed matching.