STM32F031K6U6 - 48MHz Cortex-M0 MCU 32KB Flash | STMicroelectronics
MPN: STM32F031K6U6 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.92 | $1.92 |
| 10 | $1.73 | $17.30 |
| 100 | $1.54 | $154.00 |
| 500 | $1.38 | $690.00 |
| 1,000 | $1.24 | $1,240.00 |
STM32F031K6U6 Overview
A microcontroller (MCU) is a single-chip embedded processor combining a CPU core, memory, and programmable peripherals. The STM32F031K6U6 belongs to the STM32F0 entry-level family within the STM32 MCU ecosystem, positioned as a migration path from 8-bit and 16-bit MCUs to 32-bit ARM performance. It shares tooling, HAL libraries, and STM32CubeMX configuration software with the wider STM32 portfolio, simplifying future upgrades.
Key features include a 12-bit ADC with up to 13 channels, 9 timers, and standard communication interfaces: one I2C, one SPI/I2S, and one USART. The device operates from a 2.0V to 3.6V single supply with integrated POR/PDR reset, and offers a CRC calculation unit and DMA controller for data movement without CPU intervention. Real-time performance is supported by a nested vectored interrupt controller (NVIC) and single-cycle multiplier.
The Cortex-M0 architecture executes Thumb instruction sets with deterministic interrupt latency, making the device suitable for real-time control loops. The UFQFPN-32 (QFN family) surface-mount package provides a small 5x5 mm footprint with an exposed thermal pad for grounding, ideal for space-constrained boards. Operating temperature spans -40C to +85C for industrial reliability.
Typical applications include industrial control, consumer appliances, IoT sensor nodes, small motor control, and power-management subsystems, where low cost, low power consumption, and adequate peripheral integration matter most.
Design tip: decouple VDD pins with 100nF ceramics plus a bulk capacitor, feed VDDA from a clean analog supply to preserve ADC accuracy, and keep NRST properly filtered per the ST datasheet layout guidelines for EMI-robust designs.
Drop-in alternatives for STM32F031K6U6 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
STM32F038K6U6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM32F042K6U6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
STM32F031K4U6
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
HK32F031K6U6
✅ Drop-In📋 Reference alternative (not in catalog)
STM32G031K6U6
⚡ Same Package📋 Reference alternative (not in catalog)
STM32F031K6U6 Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M0 32-bit |
| Core Size | 32-bit |
| Maximum Clock Frequency | 48 MHz |
| Flash Memory | 32 KB |
| SRAM | 4 KB |
| Supply Voltage Range | 2.0 V to 3.6 V |
| ADC Resolution | 12-bit, up to 13 channels |
| Timers | 9 (including advanced-control) |
| Communication Interfaces | 1x I2C, 1x SPI/I2S, 1x USART |
| DMA | Yes |
| CRC Unit | Yes |
| Package | 32-UFQFPN (5x5 mm), exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C |
| Oscillator | 4 to 32 MHz crystal oscillator |
| Reset | POR/PDR integrated |
| RoHS Status | Compliant |
STM32F031K6U6 Pin Configuration
| Pin 1 | VDD/VDDA — Power supply 2.0V to 3.6V |
| Pin 2 | PF0/OSC_IN — Oscillator input or GPIO |
| Pin 3 | PF1/OSC_OUT — Oscillator output or GPIO |
| Pin 4 | NRST — Bidirectional reset, active low |
| Pin 5 | PA0 — GPIO / ADC channel / WKUP |
| Pin 6 | PA1 — GPIO / ADC channel |
| Pin 7 | PA2 — GPIO / USART TX |
| Pin 8 | PA3 — GPIO / USART RX |
| Pin 14 | PA13/SWDIO — Serial wire debug data I/O |
| Pin 15 | PA14/SWCLK — Serial wire debug clock |
| Pin 16 | PA15 — GPIO / SPI NSS |
| Pin 32 | VSS / EP — Ground, exposed pad |
Typical Applications
STM32F031K6U6 is suitable for 6 applications: IoT Sensor Nodes, Small Motor Control, Industrial Control and Automation, Consumer Appliances, Power Management Subsystems, Human-Machine Interface (HMI) Boards.
IoT Sensor Nodes
The STM32F031K6U6 fits battery-powered IoT sensor nodes because its 48 MHz Cortex-M0 core offers just enough compute for sensor sampling and filtering while drawing minimal power from a 2.0V to 3.6V supply. Its 12-bit ADC with 13 channels digitizes analog sensors directly, and the I2C/SPI/USART interfaces connect RF modules or external memory. Running bare-metal firmware in the 32 KB Flash with sleep-mode duty cycling extends battery life, and the small 5x5 mm UFQFPN-32 package suits compact node PCBs.
Recommended
Small Motor Control
With 9 timers including advanced-control timers for PWM generation, plus a 12-bit ADC for current and position feedback, the STM32F031K6U6 implements trapezoidal or basic sensorless BLDC control in appliances, fans, and small pumps. The 48 MHz core executes commutation loops deterministically via the NVIC, while PWM dead-time features protect the power stage. Its UART interface supports host communication, and the 32 KB Flash stores control firmware with room for diagnostics. The exposed-pad UFQFPN-32 package simplifies thermal grounding on motor-driver PCBs.
Recommended
Industrial Control and Automation
In industrial control panels, the STM32F031K6U6 serves as a low-cost interface MCU handling button inputs, relay outputs, and RS-485 or UART communication to a PLC host. The -40C to +85C temperature range and integrated POR/PDR ensure reliable operation in electrically noisy cabinets, while the CRC unit validates communication frames without CPU cycles. The 32 KB Flash accommodates state-machine firmware, and SWD via PA13/PA14 allows field programming. Solid decoupling of VDD/VDDA per ST layout guidelines preserves ADC accuracy in noisy environments.
Recommended
Consumer Appliances
The STM32F031K6U6 provides appliance-control brains for coffee makers, small pumps, hair styling tools, and chargers, where BOM cost is decisive. Its single USART handles user-interface or master-board communication, the 12-bit ADC reads temperature sensors and potentiometers, and timers generate PWM for heaters, LEDs, or small motors. Operating down to 2.0V allows direct battery operation, and the 5x5 mm UFQFPN-32 package fits dense consumer PCBs. STM32CubeMX and HAL libraries shorten development cycles, keeping total engineering cost low for high-volume products.
Recommended
Power Management Subsystems
The STM32F031K6U6 acts as a supervisory and sequencing MCU in power-management subsystems, monitoring voltages via its 12-bit ADC, generating PWM for bias supplies or fan control, and communicating status over UART or I2C to a system host. The DMA controller offloads ADC sampling from the CPU, and the CRC unit protects telemetry frames. Its wide 2.0V to 3.6V operating range and sleep modes keep standby consumption minimal. When paired with ST-compatible gate drivers and regulators, it forms a complete low-cost digital power control node.
Recommended
Human-Machine Interface (HMI) Boards
As the controller of small HMI boards with buttons, LEDs, and status indicators, the STM32F031K6U6 scans keypads through its GPIO matrix, drives LED PWM dimming from its timers, and reports events via USART to a main system controller. The 48 MHz core provides responsive debounce and menu logic, while the 4 KB SRAM holds display buffers for simple segment or OLED controllers on I2C/SPI. SWD programming on PA13/PA14 enables in-field firmware updates, and the compact UFQFPN-32 footprint suits thin front-panel PCB assemblies in consumer and industrial products.
Recommended
Recommended Products Summary
Engineering reference data for STM32F031K6U6 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM32F038K6U6 | STM32F042K6U6 | HK32F031K6U6 | STM32G031K6U6 |
|---|---|---|---|---|---|
| Package | 32-UFQFPN (5x5 mm) | 32-UFQFPN (5x5 mm) - same | 32-UFQFPN (5x5 mm) - same | 32-UFQFPN (5x5 mm) - same | 32-UFQFPN (5x5 mm) - same footprint, different pinout |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | HOLYCHIP (HK) | STMicroelectronics |
| Core | ARM Cortex-M0 @ 48 MHz | ARM Cortex-M0 @ 48 MHz | ARM Cortex-M0 @ 48 MHz | ARM Cortex-M0 @ 48 MHz (claimed) | ARM Cortex-M0+ @ 64 MHz |
| Flash | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| USB | No | No | Yes (crystal-less FS device) | No | No |
| Drop-in Replacement | - | Yes | Yes (verify per design) | Yes (sample-test recommended) | No - redesign required |
Key Differentiators
- Lowest-cost F0 family member with DMA and CRC (vs STM32F038K6U6)
- Lower total cost than USB-capable sibling (vs STM32F042K6U6)
- Mature ST ecosystem vs cross-brand equivalents (vs HK32F031K6U6)
Design Notes
Decouple each VDD pin with a 100nF ceramic capacitor placed within 2mm of the pin, plus one 4.7uF bulk capacitor per supply domain. Connect VDDA to VDD through a filter (ferrite bead or 10-ohm resistor with 1uF+10nF) to maintain ADC accuracy, since the 12-bit ADC shares its reference path with VDDA. Ensure the 2.0V-3.6V supply stays within spec during brownouts; the integrated POR/PDR handles reset but not supply dips below 2.0V.
Solder the UFQFPN-32 exposed pad to a solid ground plane for thermal dissipation and EMI performance - do not leave it floating. Use short return paths for the SWD pins (PA13/PA14) if programming connectors are off-board. Keep the NRST line short with a 100nF pull-down capacitor per ST recommendation; avoid routing it near switching nodes. A continuous ground plane under the QFN reduces loop area for fast GPIO edges.
The STM32F031 family has no USB and limited flash (32KB), so firmware written for larger F0/F1 parts may not fit - check code size early. GPIO pin functions in the UFQFPN-32 are heavily remapped versus larger packages; verify the pin-mapping table in the datasheet, not the family reference manual alone. Debug via SWD only (no JTAG on this device). Also, HSI accuracy is about 1% - do not use it for precision USART baud rates without correction.
Compliance Information
RoHS compliant per distributor listings (DigiKey/Mouser). Not an automotive AEC-Q100 qualified part.
