What the LM3S2139-IBZ25-A2 is and where it fits
The Texas Instruments LM3S2139-IBZ25-A2 is a 32-bit ARM Cortex-M3 MCU from the Stellaris® series, clocked at 25 MHz with 64 KB of Flash program memory and 16K x 8 of SRAM. It carries a full set of serial interfaces including CANbus, I²C, IrDA, Microwire, SPI, SSI, and UART/USART, plus four 10-bit ADC channels and 56 general-purpose I/O lines. The part is rated for the -40°C to 85°C industrial temperature range and is supplied in a 108-ball BGA (10x10 mm) package — a footprint common on mid-density Stellaris controllers. Typical applications include industrial control nodes, CAN-based sensor hubs, and embedded networking endpoints where a moderate-speed Cortex-M3 with broad peripheral integration is needed.
25 MHz core — what it means for the design
The 25 MHz clock rate places this MCU in the moderate-throughput tier of the Stellaris family — adequate for command-and-response control loops, CAN message handling, and sensor aggregation, but not for heavy DSP or high-frame-rate graphics. The 64 KB Flash and 16K x 8 RAM suit firmware images with moderate feature sets; designs needing more code space or faster execution should look at higher-speed siblings in the same BGA footprint.
NRND — what that means for procurement
The LM3S2139-IBZ25-A2 carries an NRND (Not Recommended for New Designs) status from Texas Instruments. This is not a full EOL notice — the part is still available through distribution for existing production runs — but it signals that the manufacturer is winding down support and that new designs should not start with this device. A formal last-time-buy window may already be in effect; buyers with active BOM lines should secure their forecast quantity now and evaluate a migration path. No official pin-compatible successor has been published for this specific variant.