80 MHz Cortex-M3 with 128 KB Flash — what it means for the BOM
The LM3S5K31-IQC80-C5T is a Texas Instruments Stellaris ARM Cortex-M3 MCU running at 80 MHz with 128 KB of Flash program memory and 24 KB of RAM. It carries a full set of serial interfaces — CAN, USB, UART, SPI, I2C, IrDA, LIN, and Microwire — plus a 16-channel 10-bit ADC and PWM outputs. The industrial temperature range (-40°C to 85°C) suits it for factory automation, motor control, and outdoor telecom equipment where the ambient can swing. The 100-pin LQFP package (14x14 mm) is a standard footprint for mid-complexity control boards.
Obsolete — sourcing through surplus channels
This part is marked obsolete by the manufacturer. No last-time-buy window remains open; the only supply path is the independent surplus and broker market. We source it to order against an RFQ — availability and current pricing are confirmed at quote time. If you are freezing a BOM for a new design, look for a current-production Cortex-M3 or Cortex-M4 from TI's Tiva or Stellaris successor families; for a legacy repair or a production run that cannot requalify, we can quote the LM3S5K31-IQC80-C5T against your volume and delivery window.
Connectivity and peripheral set
The MCU integrates CAN, USB, UART, SPI, I2C, IrDA, LIN, and Microwire interfaces. The 16-channel 10-bit ADC samples for motor current sensing or analog input scanning.
Supply voltage and power considerations
Core and I/O run from a single 1.08 V to 1.32 V supply. The internal oscillator eliminates an external crystal for many applications.