80 MHz Cortex-M3 with 128 KB Flash – what it means for the BOM
The LM3S5K31-IQC80-C1 is a 32-bit ARM Cortex-M3 MCU from the Stellaris 5000 series, clocked at 80 MHz with 128 KB Flash and 24K x 8 SRAM. The 80 MHz core delivers enough throughput for motor-control loops, CAN-based industrial networks, and USB data-logging applications without external memory expansion. The 128 KB Flash is sized for mid-complexity firmware stacks; the 24K x 8 SRAM leaves headroom for moderate buffering in communication protocols.
Obsolete – sourcing through independent channels
This part is officially obsolete per the manufacturer's product status. No direct replacement has been listed in the available records. For existing BOM lines, the part is sourced through independent distribution on a quoted-to-order basis against an RFQ. Availability and current pricing are confirmed at quote time. The Stellaris family has been discontinued; a replacement would require a pin-compatible migration to a newer TI Cortex-M4F or another ARM MCU.
Connectivity and peripheral set
The LM3S5K31 includes CAN, I²C, SPI, SSI, UART, IrDA, and USB interfaces, plus a QEI for motor feedback. The internal oscillator eliminates the need for an external crystal. The 16-channel 10-bit ADC samples at rates suitable for current sensing and temperature monitoring in industrial drives. Brown-out detection and POR are built in, reducing external supervisor IC count.