Texas Instruments has marked the LM3S1Z16-IQR50-C3 as Obsolete.
Core and memory — 50MHz Cortex-M3 with 16KB Flash
The ARM Cortex-M3 core runs at 50MHz, delivering a 32-bit single-core pipeline with 16KB of on-chip Flash program memory (16K x 8) and 6K x 8 of SRAM. For a compact control loop or sensor hub, the 6KB RAM holds a modest RTOS footprint plus a few hundred bytes of stack — budget accordingly if the application layer is heavy.
33 digital I/O lines are available, alongside an 8-channel 10-bit A/D converter for analog sensor inputs. The connectivity block covers I²C, SPI, SSI, UART/USART, IrDA, LINbus, and Microwire — enough for a mixed-signal control board with a few serial peripherals and a fieldbus link. On-chip peripherals include brown-out detect/reset, DMA, POR, PWM, and a watchdog timer. The internal oscillator eliminates an external crystal for the core clock, though the ADC accuracy depends on the internal RC stability.
Package and supply — 64-LQFP, 1.08V–1.32V core
Housed in a 64-LQFP with a 10x10 mm body (supplier device package 64-LQFP (10x10)). The 0.50 mm pitch demands a 4-layer board for clean fan-out of the inner rows — two-layer breaks out only the perimeter pins. Core supply is 1.08V to 1.32V — a tight 240 mV window. A local LDO or precision switcher is needed; a 1.2V rail with ±5% tolerance keeps the core inside spec.