STMicroelectronics STM32F091RCT6J

Overview

STM32F091RCT6J from STMicroelectronics is a 32-bit ARM Cortex-M0 microcontroller with 256 KB Flash, 32 KB SRAM, integrated CAN 2.0B interface, dual 12-bit DACs, and 12-bit ADC (1.0 µs conversion) - deployed in industrial motor control, smart metering, and CAN-based building automation systems.

For engineers reviewing the STM32F091RCT6J datasheet, STM32F091RCT6J pinout, STM32F091RCT6J application, or STM32F091RCT6J equivalent, key selection criteria include CAN timing compliance, 5V-tolerant I/O count (69 pins), RTC+backup register retention under VBAT, and SWD debug support for firmware validation in safety-critical embedded designs.

Technical Context

The device integrates an ARM Cortex-M0 core running at up to 48 MHz, supported by internal 48 MHz oscillator with automatic trimming, 8 MHz RC + x6 PLL, and 32 kHz RTC crystal oscillator. Memory subsystem includes 256 KB Flash with ECC protection and 32 KB SRAM with hardware parity checking.

Peripheral architecture features one advanced-control timer (TIM1) for 6-channel PWM, two I²C interfaces (one Fast Mode Plus at 1 Mbit/s), eight USARTs (three with ISO7816/LIN/IrDA), two SPI/I²S modules, and HDMI-CEC wakeup capability - all coordinated via a 12-channel DMA controller and nested vectored interrupt controller (NVIC).

Key Specifications

Pinout & Package

LQFP64 package (10 × 10 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 STM32F091RCT6J, STM32F072RBT6 trades CAN and dual DAC for lower cost and simpler design, while STM32F303RCT6 adds FPU and ADC speed at the expense of CAN integration and higher power - making the F091 optimal for cost-sensitive, CAN-centric industrial nodes requiring analog precision and low-power RTC operation.

Availability

STM32F091RCT6J is available at Aetrix Electronics and suitable for industrial motor control, smart energy metering, building automation nodes, and medical diagnostic interfaces requiring stable component supply across multi-year production cycles.

Supply support for STM32F091RCT6J 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, and MEMS sensors for industrial, automotive, and consumer markets.

This part belongs to the STM32F0 mainstream Arm Cortex-M0 series, engineered for cost-sensitive, resource-constrained embedded applications demanding high peripheral integration, low-power operation, and industrial-grade reliability.

FAQ

Does STM32F091RCT6J support USB connectivity?

No - the STM32F091RCT6J does not integrate a USB peripheral. It features CAN, multiple USARTs (including ISO7816 and IrDA), I²C, and SPI interfaces. For USB host/device functionality, designers must select an STM32F07x or STM32F30x variant with dedicated USB FS controller and internal PHY.

What is the maximum operating frequency of the internal HSI48 oscillator?

The internal HSI48 oscillator operates at a nominal 48 MHz with automatic trimming against an external clock source (e.g., USB SOF or LSE). Its accuracy is ±0.25% over temperature and voltage when synchronized, enabling reliable USB-less clocking for CAN and SPI timing without external crystals.

Can the 12-bit DAC outputs drive a speaker directly?

No - the DAC outputs (PA4/PA5) are buffered voltage sources with 1 µA load capability and no current drive strength. Driving even a small speaker requires external amplification (e.g., Class-D amplifier IC or op-amp buffer) to deliver sufficient current and impedance matching.

Is the RTC calendar function battery-backed when VDD is removed?

Yes - when VBAT is supplied (1.65–3.6 V), the RTC continues running and retains calendar date/time, alarm settings, and 4 KB of backup SRAM contents even with VDD disconnected. This requires proper decoupling and diode-or configuration to prevent backfeed during main power loss.