Stellaris ARM Cortex-M3 at 50 MHz — what this part delivers
The Texas Instruments LM3S1850-IBZ50-A2T is a 32-bit ARM Cortex-M3 MCU from the Stellaris series, clocked at 50 MHz with 256 KB of Flash program memory and 32 KB of SRAM. It integrates a full set of serial interfaces — I²C, SPI, SSI, UART/USART, IrDA, and Microwire — plus a quadrature encoder interface (QEI) for motor-position feedback. On-chip peripherals include brown-out detect, POR, PWM, and a watchdog timer, all running from a 2.25 V to 2.75 V supply. The 56 GPIOs are brought out to a 108-ball BGA package (10x10 mm), and the part is rated for the -40°C to 85°C industrial temperature range.
NRND — no longer recommended for new designs
The LM3S1850-IBZ50-A2T carries a Not Recommended for New Designs (NRND) lifecycle status. This means Texas Instruments will continue to support existing production builds for a defined window, but the part is not intended for new design-ins. For a BOM line that needs to stay active, the NRND flag signals that a last-time-buy window is finite, and any replacement strategy should be underway. The part is sourced and quoted to order through independent distribution — availability and current pricing are confirmed at quote time against an RFQ.
The 56 GPIOs, combined with the QEI and PWM peripherals, make this a natural fit for brushless DC motor control with encoder feedback — a common Stellaris deployment pattern. The internal oscillator eliminates the need for an external crystal in non-timing-critical applications, saving two pins and a few cents on the BOM.