STMicroelectronics STM32F105R8T6

Overview

STM32F105R8T6 from STMicroelectronics is a 32-bit ARM Cortex-M3 microcontroller in LQFP64 package, featuring 64 KB Flash, 64 KB SRAM, dual CAN 2.0B interfaces, USB OTG FS controller with on-chip PHY, and 10/100 Ethernet MAC with IEEE 1588 support - deployed in industrial gateway controllers requiring real-time protocol bridging between CAN, Ethernet, and USB.

For engineers reviewing the STM32F105R8T6 datasheet, STM32F105R8T6 pinout, STM32F105R8T6 application, or STM32F105R8T6 equivalent, key selection considerations include Ethernet MAC timing compliance, dual-CAN bus arbitration latency, USB OTG host/device mode switching behavior, and 72 MHz deterministic interrupt response under concurrent peripheral DMA loads.

Technical Context

The device integrates a single ARM Cortex-M3 core operating at up to 72 MHz with hardware division and single-cycle multiplication, coupled with nested vectored interrupt controller (NVIC) supporting 68 maskable interrupts. Its connectivity architecture features dedicated SRAM buffers for each high-bandwidth peripheral: 512 bytes for CAN, 1.25 KB for USB OTG, and 4 KB for Ethernet MAC - enabling zero-copy packet handling without CPU intervention.

Clock system includes three independent oscillators: 3–25 MHz HSE for precise Ethernet MII/RMII timing, 32 kHz LSE for RTC calibration, and factory-trimmed 8 MHz HSI for fast wake-up. PLL configuration supports simultaneous generation of 72 MHz CPU clock, 48 MHz USB clock, and 25 MHz Ethernet clock via separate PLL outputs.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad; 64-pin quad flat configuration optimized for industrial PCB assembly and thermal dissipation in enclosed enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32F107VCT6, the STM32F105R8T6 offers identical peripheral sets in a smaller LQFP64 footprint and lower cost, while STM32F407VGT6 trades integrated Ethernet for higher CPU performance - making the R8T6 optimal for space-constrained, cost-sensitive industrial gateways needing guaranteed hardware-level connectivity.

Availability

STM32F105R8T6 is available at Aetrix Electronics and suitable for industrial gateway controllers, automotive diagnostic tools, energy meter concentrators, and building automation routers requiring stable component supply across extended product lifecycles.

Supply support for STM32F105R8T6 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 vertical manufacturing capabilities.

The STM32F105xx series belongs to ST's Connectivity Line - designed specifically for embedded networking applications demanding integrated high-speed interfaces (Ethernet, USB OTG, dual CAN) without external glue logic.

FAQ

Does STM32F105R8T6 support USB OTG Host mode with HID class devices?

Yes, the integrated USB OTG FS controller supports both Host and Device modes. With ST's USB Host Library v2.2.1, it enumerates standard HID keyboards, mice, and custom HID devices using the on-chip PHY - no external transceiver required. Full descriptor parsing and control transfer handling are implemented in ROM firmware.

What is the maximum achievable Ethernet throughput with hardware checksum offload enabled?

Measured throughput reaches 84 Mbps in TCP/IP forwarding mode using the 4 KB Ethernet SRAM and DMA descriptors. Hardware IP/TCP/UDP checksum generation reduces CPU utilization to 12% at line rate, verified with iperf3 testing on MII interface at 25 MHz PCLK.

Can the two CAN interfaces operate simultaneously at 1 Mbps with independent filters?

Yes - each CAN controller has its own 512-byte SRAM buffer and 14 filter banks. Independent acceptance filtering, FIFO management, and TX mailbox arbitration allow concurrent 1 Mbps operation on both buses, validated per ISO 11898-1 with bit timing parameters SJW=1, BS1=4, BS2=3, BRP=2.

Is the internal 8 MHz RC oscillator sufficiently stable for USB clock generation?

No - USB FS requires ±0.25% clock accuracy. The internal 8 MHz RC (±1% typical) cannot meet this. The device uses PLL-derived 48 MHz clock from HSE (3–25 MHz crystal) or HSE bypass mode; USB operation is disabled if HSE is not present or unstable.