The Texas Instruments LM3S5D91-IBZ80-A1 is a 32-bit ARM Cortex-M3 MCU from the Stellaris 5000 series, clocked at 80 MHz with 512 KB of Flash and 96 KB of SRAM. It integrates USB OTG, CAN, and Ethernet connectivity alongside 72 general-purpose I/O lines, making it suited for industrial control nodes, motor drives, and building-automation gateways that need a single-chip networking stack. The 108-LFBGA (10x10 mm) package keeps the footprint compact for space-constrained PCBs.
80 MHz core — what it means for the control loop
The 80 MHz Cortex-M3 core delivers enough throughput to run a real-time control loop (e.g., a field-oriented motor controller) alongside a lightweight TCP/IP stack and CANopen master. With 96 KB SRAM, the data buffer budget is adequate for a few hundred process variables but not for large frame buffers or extensive logging — plan your heap and stack allocation early.
Obsolete — sourcing reality
Connectivity and peripherals — what fits
The part includes CAN, USB OTG, Ethernet, and multiple serial interfaces (I²C, SPI, SSI, UART, IrDA, LIN, Microwire, QEI). The 16-channel 12-bit ADC handles analog feedback for current sensing or temperature monitoring. Brown-out detect, POR, and a watchdog timer are on-chip — no external supervisor needed for basic safety monitoring.
Temperature grade and environment
Rated for -40°C to 85°C ambient, this MCU suits industrial enclosures and outdoor telecom cabinets. The 108-LFBGA package demands careful PCB layout for solder-joint reliability under thermal cycling.