STMicroelectronics STM32F042K6U6TR

Overview

STM32F042K6U6TR from STMicroelectronics is an ARM® Cortex®-M0 32-bit microcontroller with 32 KB Flash, 6 KB SRAM, crystal-less USB 2.0 Full-Speed interface, CAN 2.0B controller, and integrated 12-bit ADC (1.0 µs conversion time). It operates from 2.0–3.6 V, supports up to 48 MHz CPU frequency, and integrates RTC with alarm and wakeup from Stop/Standby-used in industrial sensor nodes requiring embedded USB-CDC communication and CAN bus interfacing.

For engineers reviewing the STM32F042K6U6TR datasheet, STM32F042K6U6TR pinout, STM32F042K6U6TR application, or STM32F042K6U6TR equivalent, key selection criteria include USB FS timing tolerance without external crystal, CAN transceiver integration readiness, 5 V-tolerant I/O count (up to 24), internal 48 MHz oscillator trimming accuracy (±0.25% over temperature), and capacitive touch sensing channel support (up to 14 channels).

Technical Context

The device implements a single-cycle ARM Cortex-M0 core with NVIC supporting 32 interrupt vectors, coupled with a clock recovery system (CRS) that synchronizes the internal 48 MHz HSI48 oscillator to USB SOF packets-enabling crystal-less USB operation. Its power architecture includes independent VDDA (2.4–3.6 V) for analog peripherals and programmable VDDIO2 supply (1.65–3.6 V) for selected I/O banks.

Peripheral integration follows ST's STM32F0-series architecture: one advanced-control timer (TIM1) with six-channel PWM and complementary outputs, two USARTs (one with ISO7816/LIN/IrDA), two SPIs (one multiplexed with I2S), and a dedicated HDMI-CEC interface with header-detection wakeup. The TSC peripheral supports self-capacitance measurement across up to 14 GPIOs without external components.

Key Specifications

Pinout & Package

STM32F042K6U6TR is housed in a 32-pin UFQFPN package (5 × 5 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per ST's DocID025832 Rev 5, Section 4 (Pinouts and pin descriptions), Table 13.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F042F6TR, the K6U6TR offers smaller footprint and VDDIO2 flexibility but fewer I/Os; versus STM32F072CBT6, it trades Flash/RAM headroom for integrated CAN-making it optimal for compact, CAN-enabled USB edge devices.

Availability

STM32F042K6U6TR is available at Aetrix Electronics and suitable for industrial sensor nodes, USB-CDC gateways, automotive body control modules, and capacitive touch panels requiring stable component supply and long-term manufacturability.

Supply support for STM32F042K6U6TR 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, specializing in microcontrollers, power management, and automotive ICs-with over 40 years of embedded systems expertise.

This part belongs to the STM32F0 mainstream Arm Cortex-M0 series, designed for cost-sensitive, low-power industrial and consumer applications requiring rich analog integration, USB connectivity, and robust real-time control.

FAQ

Does STM32F042K6U6TR require an external crystal for USB operation?

No. It uses the internal 48 MHz HSI48 oscillator with automatic trimming synchronized to USB Start-of-Frame (SOF) packets via the Clock Recovery System (CRS). This eliminates the need for an external 48 MHz crystal, reducing component count and PCB area while maintaining ±0.25% frequency accuracy over temperature and voltage.

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

STM32F042K6U6TR supports up to 24 5 V-tolerant I/Os across GPIO ports A, B, and F. These pins tolerate 5 V input even when VDD is 2.0–3.6 V, enabling direct interfacing with legacy 5 V peripherals such as RS-232 transceivers, optocouplers, and discrete logic without level shifters.

Can the built-in TSC support mutual capacitance sensing?

No. The Touch Sensing Controller (TSC) in STM32F042K6U6TR supports only self-capacitance measurement (charge transfer method) across up to 14 channels. Mutual capacitance requires external driver ICs or higher-tier STM32 series (e.g., STM32G0/G4) with dedicated CSD peripherals.

Is the CAN interface compatible with ISO 11898-1 physical layer?

The CAN controller implements ISO 11898-1 protocol layer only. Physical layer compliance requires an external CAN transceiver (e.g., TJA1042, SN65HVD230) connected to PB8 (CAN_RX) and PB9 (CAN_TX). The MCU handles bit timing, arbitration, error handling, and message filtering in hardware.