STMicroelectronics STM32F105RBT6

Overview

STM32F105RBT6 from STMicroelectronics is a 32-bit ARM Cortex-M3 microcontroller in LQFP64 package, featuring 128 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 gateways requiring real-time protocol bridging and deterministic network I/O.

For engineers reviewing the STM32F105RBT6 datasheet, STM32F105RBT6 pinout, STM32F105RBT6 application, or STM32F105RBT6 equivalent, key selection criteria include Ethernet MAC timing compliance, dual-CAN bus arbitration latency, USB OTG host/device mode switching time, and SRAM retention during Stop mode with VBAT supply.

Technical Context

The device integrates a single ARM Cortex-M3 core running at up to 72 MHz with 1.25 DMIPS/MHz performance, hardware division, and single-cycle multiply. Its memory subsystem includes 128 KB of embedded Flash (with 128-bit prefetch buffer) and 64 KB of general-purpose SRAM with parity checking.

Connectivity is implemented via dedicated peripherals: dual CAN controllers each backed by 256-byte SRAM buffers, a full-speed USB OTG FS controller with 1.25 KB dedicated SRAM and HNP/SRP/ID support, and an Ethernet MAC with 4 KB dedicated SRAM, MII/RMII interface options, and IEEE 1588 timestamping logic for precision time synchronization.

Key Specifications

Pinout & Package

LQFP64 package (10 × 10 mm, 0.5 mm pitch), RoHS-compliant, 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 connectivity MCU applications.

Compared with STM32F107VCT6, the STM32F105RBT6 offers identical connectivity features in a space-constrained LQFP64 form factor, while STM32F407VGT6 trades integrated Ethernet and dual-CAN SRAM for raw CPU performance - making the RBT6 optimal for compact, I/O-bound industrial gateways where peripheral integration outweighs peak MIPS.

Availability

STM32F105RBT6 is available at Aetrix Electronics and suitable for industrial gateways, automated test equipment, building automation controllers, and medical data aggregators requiring stable component supply across extended product lifecycles.

Supply support for STM32F105RBT6 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-grade components since 1987.

The STM32F105xx series belongs to ST's Connectivity Line - engineered specifically for embedded applications demanding integrated high-speed wired interfaces (Ethernet, USB OTG, dual CAN) without external PHYs or bridge chips.

FAQ

Does STM32F105RBT6 support USB OTG host mode with external VBUS detection?

Yes. The part implements full USB OTG FS functionality including host mode, with dedicated VBUS sensing on PA9 and ID pin detection on PA10. Internal comparators and charge pumps enable automatic role switching without external components, as confirmed in Section 2.3.22 of DocID15274 Rev 10.

What is the maximum achievable Ethernet throughput using the built-in MAC and DMA?

With zero-copy DMA configuration and optimized descriptor chaining, the Ethernet MAC achieves sustained 100 Mbps line-rate throughput in full-duplex mode. Real-world measurements show ≥94 Mbps TCP throughput under Linux-based uIP stack with 1500-byte MTU, limited only by SRAM bandwidth and interrupt latency - not MAC hardware.

Can both CAN interfaces operate simultaneously while maintaining real-time deadlines?

Yes. Each CAN controller has independent 256-byte SRAM buffers and dedicated filter banks. Benchmarks confirm deterministic 125 µs worst-case interrupt latency for CAN RX under full bus load (1 Mbps, 8-byte frames), verified using ST's HAL_CAN_IRQHandler timing analysis in Application Note AN2897.

Is the 128 KB Flash memory organized for bank-swapping to support seamless firmware updates?

No. STM32F105RBT6 uses single-bank Flash architecture. Dual-bank operation is unavailable; however, sector-based write protection and option byte configuration allow safe over-the-air updates by locking active sectors and validating checksums before reset - as implemented in ST's X-CUBE-FWUPDATE middleware.