STMicroelectronics STM32F042C6T7

Overview

STM32F042C6T7 from STMicroelectronics is a 32-bit ARM Cortex-M0 microcontroller with 32 KB Flash, 6 KB SRAM, crystal-less USB 2.0 FS interface, CAN 2.0B controller, and 12-bit ADC (1.0 µs conversion). It operates from 2.0–3.6 V, supports up to 48 MHz CPU frequency, and integrates RTC with alarm, 9 timers (including advanced-control TIM1), and capacitive touch sensing for HMI applications in industrial control panels.

For engineers reviewing the STM32F042C6T7 datasheet, STM32F042C6T7 pinout, STM32F042C6T7 application, or STM32F042C6T7 equivalent, key selection criteria include USB 2.0 FS operation without external crystal, CAN bus integration, 5 V-tolerant I/O count (up to 24), low-power Stop/Standby modes with RTC wake-up, and LQFP48 package compatibility with legacy STM32F0 design layouts.

Technical Context

The STM32F042C6T7 implements an ARM Cortex-M0 core with Harvard architecture, supporting Thumb-2 instruction set and NVIC with 32 interrupt lines. Its clock system includes dual oscillators: a 48 MHz internal HSI48 (auto-trimmed via USB SOF) for crystal-less USB operation and a 32 kHz LSE for RTC calibration.

Peripheral interconnect uses AHB/APB buses with DMA channel arbitration for concurrent ADC sampling, USB data transfer, and CAN message buffering. The device features hardware CRC calculation unit, independent watchdog (IWDG), and system window watchdog (WWDG) - all synchronized to dedicated low-speed clocks for deterministic fail-safe timing.

Key Specifications

Pinout & Package

LQFP48 package (7 × 7 mm, 0.5 mm pitch), RoHS-compliant ECOPACK®2, rated for industrial temperature range (–40 °C to +85 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F072CBT6, the STM32F042C6T7 trades Flash/SRAM capacity for crystal-less USB integration and lower unit cost; versus STM32G031K8T6, it retains CAN at the expense of modern security features - making it optimal for established industrial CAN+USB gateway designs.

Availability

STM32F042C6T7 is available at Aetrix Electronics and suitable for industrial HMI panels, USB-CAN bridge devices, and smart power outlets requiring stable component supply across multi-year production cycles.

Supply support for STM32F042C6T7 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 automotive semiconductors since 1987.

The STM32F0 series targets cost-sensitive, resource-constrained embedded applications requiring ARM Cortex-M0 performance with rich analog and communication peripherals - optimized for industrial control, appliance HMI, and USB-connected peripherals.

FAQ

Does STM32F042C6T7 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) tokens, enabling full-speed USB 2.0 device operation without any external crystal or capacitor. This is confirmed in Section 3.6 and Table 40 of the official datasheet (DocID025832 Rev 5).

What is the maximum number of 5 V-tolerant I/O pins on STM32F042C6T7?

The STM32F042C6T7 supports up to 24 5 V-tolerant I/O pins across GPIO ports A, B, and C. These pins tolerate 5 V input even when VDD is 2.0–3.6 V, allowing direct interfacing with legacy 5 V logic and sensors - verified in Section 3.7 and Table 14 of the datasheet.

Can the internal RTC maintain time during Standby mode with VBAT connected?

Yes. When VBAT is supplied (e.g., coin cell), the calendar RTC, backup registers, and LSE oscillator remain active during Standby mode, consuming <1 µA. Wake-up events (alarm, periodic) can exit Standby within 5 µs - specified in Sections 3.13 and 6.3.6 of the datasheet.

Is the CAN controller compatible with ISO 11898-1:2015 physical layer requirements?

No. The STM32F042C6T7 contains only the CAN protocol controller (bxCAN), not the physical layer transceiver. Compliance with ISO 11898-1 requires an external CAN transceiver (e.g., TJA1042 or SN65HVD230) connected to PB8 (RX) and PB9 (TX), as detailed in Section 3.18 and Figure 22 of the reference manual.