STMicroelectronics STM32F042K6U7

Overview

STM32F042K6U7 from STMicroelectronics is a 32-bit ARM Cortex-M0 microcontroller with 32 KB Flash, 6 KB SRAM, crystal-less USB 2.0 FS, CAN 2.0B interface, and 48 MHz max CPU frequency. It integrates a 12-bit 1.0 µs ADC (10 channels), nine timers including one advanced-control timer for six-channel PWM, and operates from 2.0–3.6 V supply. Used in industrial sensor nodes requiring embedded USB-CDC communication and real-time motor control.

For engineers reviewing the STM32F042K6U7 datasheet, STM32F042K6U7 pinout, STM32F042K6U7 application, or STM32F042K6U7 equivalent, key selection criteria include USB clocking autonomy (48 MHz HSI48 with trimming), CAN+USB coexistence on single-chip edge devices, 5 V-tolerant I/O count (24 pins), and capacitive touch channel support (up to 14 channels) for HMI-constrained designs.

Technical Context

The STM32F042K6U7 implements a tightly coupled ARM Cortex-M0 core with Harvard bus architecture and integrated NVIC supporting 32 interrupt lines. Its clock system combines four internal oscillators (HSI8, HSI14, HSI48, LSI) and external sources (HSE up to 32 MHz, LSE 32.768 kHz), with automatic HSI48 trimming via USB SOF synchronization enabling crystal-less full-speed USB operation.

Peripheral interconnect uses AHB/APB2/APB1 buses with DMA controller routing transfers between memory, ADC, timers, and communication interfaces. The device supports dual-supply I/O domains (VDDIO2 for 8 pins at 1.65–3.6 V) and includes hardware CRC unit, independent/system watchdogs, and calendar RTC with alarm and wake-up from Stop/Standby modes.

Key Specifications

Pinout & Package

STM32F042K6U7 is housed in UFQFPN32 (5 × 5 mm, 0.5 mm pitch) package with 32-pin layout optimized for compact industrial and consumer modules. Pin functions are fully configurable via GPIO alternate function registers (AFR), supporting remapping of critical peripherals including USB D+/D−, CAN TX/RX, and USART/UART signals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F042F6T7, the K6U7 offers superior space efficiency and lower thermal resistance in UFQFPN32, while STM32F072CBT6 trades pin compatibility for expanded memory and peripheral set - neither matches the K6U7's optimal balance of USB autonomy, CAN integration, and compact packaging for embedded edge nodes.

Availability

STM32F042K6U7 is available at Aetrix Electronics and suitable for industrial sensor nodes, USB-CDC diagnostic tools, capacitive touch remotes, and BLDC motor actuators requiring stable component supply across multi-year production cycles.

Supply support for STM32F042K6U7 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 broad industrial certification coverage.

The STM32F0 series targets cost-sensitive, resource-constrained embedded applications demanding high integration, ultra-low-power operation, and USB/CAN connectivity - designed specifically for smart sensors, HMI peripherals, and industrial edge nodes.

FAQ

Does STM32F042K6U7 support USB device mode without an external crystal?

Yes. The device integrates an HSI48 oscillator with automatic trimming based on USB Start-of-Frame (SOF) synchronization, achieving ±0.25% accuracy required for USB 2.0 Full-Speed compliance. No external 48 MHz crystal or oscillator is needed, reducing BOM cost and PCB layout complexity.

What is the maximum number of 5 V-tolerant I/Os on STM32F042K6U7?

The STM32F042K6U7 provides up to 24 5 V-tolerant I/O pins across GPIO ports A, B, and F. These pins tolerate 5 V inputs while operating from a 3.3 V supply, enabling direct interfacing with legacy 5 V logic families and industrial sensors without external level-shifting circuitry.

Can the CAN and USB peripherals operate simultaneously on this MCU?

No - PA11 and PA12 are shared between USB DP/DM and CAN RX/TX functions and cannot be active concurrently. Software must reconfigure the GPIO alternate function to switch between modes. For simultaneous CAN+USB operation, select STM32F072 or STM32F103 with dedicated, non-overlapping pins.

What low-power modes are supported, and what is the lowest achievable current?

The device supports Sleep, Stop, and Standby modes. In Standby mode with RTC enabled and VBAT supplied, typical current is 1.8 µA. This mode retains RTC time/date and backup registers while powering down all clocks and most logic - ideal for battery-backed sensor wake-up applications.