Cortex-M3 at 50 MHz — 100-LQFP package
The Texas Instruments LM3S1538-IQC50-A2T is a Stellaris ARM Cortex-M3S 1000 series microcontroller built around a 32-bit ARM Cortex-M3 core running at 50 MHz. It carries 96 KB of on-chip Flash program memory and 64 KB of SRAM — enough headroom for a modest RTOS and application stack without external memory. Housed in a 100-LQFP package (14x14 mm body), the part exposes 43 GPIOs and a peripheral set that includes I²C, SPI, SSI, UART/USART, IrDA, Microwire, and a Quadrature Encoder Interface (QEI) for motor-feedback applications.
Texas Instruments lists the LM3S1538-IQC50-A2T as NRND (Not Recommended for New Designs). The part remains available for existing production runs, but TI advises against using it in new product development. For an existing BOM line that already carries this order code, the NRND status means the supply window is finite — plan a last-time-buy strategy or qualify a replacement before TI issues an end-of-life notice. Sourced through independent distribution channels; availability and current pricing confirmed at RFQ.
Industrial temperature grade and supply rails
On-chip peripherals include a brown-out detect/reset, POR, PWM outputs, and a watchdog timer — enough supervisory logic to run a safety-critical control loop without an external supervisor IC. An internal oscillator keeps the core clocked without a crystal, though the internal accuracy limits precision timing to the datasheet's specified tolerance.
ADC and connectivity for sensor fusion
An 8-channel 10-bit ADC captures analog sensor inputs — thermocouple, pressure transducer, or current-sense amplifier outputs — without an external converter. The QEI peripheral decodes incremental encoder pulses directly, saving a timer channel for other duties. The exposed pad is on the bottom; verify the solder-paste stencil aperture matches the datasheet land pattern to avoid voids under the die.