50 MHz Cortex-M3 with 128 KB Flash — what it means on the bench
The LM3S1751-IQC50-A2T is a Stellaris® ARM® Cortex®-M3S 1000 series microcontroller running a 32-bit single-core at 50 MHz. It carries 128 KB of Flash program memory and 64 KB of RAM. The operating temperature range is -40°C to 85°C. The supply voltage range is 2.25 V to 2.75 V.
NRND — what it means for your BOM line
The LM3S1751-IQC50-A2T carries an NRND (Not Recommended for New Designs) status. That means TI is no longer actively supporting this part for new projects, and the window for last-time-buy orders is closing — or already closed. For existing production, you are looking at the surplus and independent distribution channel to fill BOM lines. Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.
Connectivity and peripherals for industrial control
The peripheral set includes I²C, SPI, SSI, UART/USART, IrDA, and Microwire — covering most sensor and actuator interfaces in a typical control cabinet. Four 10-bit ADC channels handle analog feedback from potentiometers or current shunts. The internal oscillator saves a crystal on the BOM, though for precision timing over temperature you will want an external source. Fifty-six general-purpose I/O pins in the 100-LQFP give enough headroom for a parallel LCD interface or a bank of opto-coupled inputs. The brown-out detect and POR circuits keep the core from running wild during a supply dip — useful in an environment with motor starts or contactor dropout.