Cortex-M3 core at 50 MHz with 128 KB on-chip flash
The LM3S1637-IQC50-A2: The 100-LQFP package (14x14 mm body) keeps the footprint manageable for a 4-layer board — the 0.50 mm pitch demands careful fan-out but is standard for this density class.
43 general-purpose I/O lines give enough pins for a sensor array plus a parallel LCD or keypad matrix. The connectivity block includes I²C, SPI, SSI, UART/USART, and IrDA — enough serial channels for a multi-drop fieldbus node or a gateway aggregating several sensor streams. On-chip peripherals include a 4-channel 10-bit ADC, PWM outputs, a watchdog timer, and brown-out detect with POR — the usual set for a motor-control or industrial I/O module where the MCU handles both loop control and supervisory fault monitoring. The internal oscillator eliminates the external crystal for the core clock, saving two pins and a few cents on the BOM — but if you need a precise timebase for the UART baud rate, the external clock input is still available via the oscillator pins.
Industrial temperature grade and supply range
The 100-LQFP package has an exposed pad on the bottom — the datasheet recommends soldering it to a copper plane on the PCB for thermal relief. Without that thermal pad connection, the junction temperature rises faster under continuous ADC conversions or heavy PWM switching.
Texas Instruments has marked the LM3S1637-IQC50-A2 as obsolete. Quantities are lot-specific; we confirm availability and pricing at RFQ time. No pin-compatible drop-in replacement from TI exists — a board spin or firmware port is required if you need a current-production part.