Texas Instruments has marked the LM3S300-EQN25-C2 as Obsolete. Sourcing now runs through independent distribution — surplus inventory, broker channels, and verified stock lots.
Core and memory — what the 25 MHz buys
Built around a 32-bit ARM Cortex-M3 core clocked at 25 MHz. This is a single-core MCU from the Stellaris® ARM® Cortex®-M3S 300 series. The 25 MHz ceiling suits control-loop and sensor-fusion tasks where throughput is moderate but deterministic — think motor commutation timing or serial protocol handling. Program memory is 16 KB of on-chip flash (16K x 8). Data RAM is 4K x 8. For a firmware engineer, the 16 KB flash limits the application to a compact RTOS or bare-metal scheduler with the HAL and stack included — no room for a full TCP/IP stack or large lookup tables. The 4 KB SRAM is the working memory ceiling; a 2 KB buffer plus 1 KB stack leaves about 1 KB for global variables.
Peripherals and I/O — what connects
Serial connectivity covers I²C, Microwire, SPI, SSI, and UART/USART. This set handles common sensor buses (I²C for temperature/humidity, SPI for ADCs or displays) and asynchronous links to radios or host controllers. The Microwire interface is a legacy SPI variant — useful when mating with older EEPROMs or codec parts that still use the 4-wire protocol. The 48-LQFP package (7x7 mm) gives a reasonable pin count for a mixed-signal board — enough for a keypad matrix, a few LED indicators, and the serial peripherals without multiplexing. On-chip peripherals include brown-out detect/reset, POR, PWM, and a watchdog timer. This industrial-grade span covers outdoor enclosures, engine-bay-adjacent electronics, and factory-floor controllers.
The LM3S300-EQN25-C2 is supplied in a 48-LQFP package with a 7x7 mm body. The 0.50 mm pitch demands a 4-layer board for reliable fan-out of the inner rows — two-layer boards will struggle to route all 36 I/O plus power and ground without vias. The supplier device package is 48-LQFP (7x7). Mounting is surface-mount. Internal oscillator type is listed as Internal — no external crystal is required for the core clock, though the UART baud-rate accuracy may benefit from an external resonator if the internal RC tolerance drifts outside the ±2% window over temperature.
Sourcing posture
The LM3S300-EQN25-C2 is an obsolete Texas Instruments MCU. Sourcing is through independent distribution channels — surplus stock, broker lots, and verified inventory. Lead time and pricing are confirmed when the RFQ is placed against the specific quantity and date.