The LM3S9B81-IBZ80-C5T is a Texas Instruments Stellaris series 32-bit ARM Cortex-M3 MCU clocked at 80 MHz.
The 108-BGA (10x10 mm) package means visual inspection and X-ray verification are critical — date-code consistency and factory-original laser marking should be confirmed before accepting stock, especially for a mature, end-of-life part that may have been sitting in uncontrolled storage.
108-BGA package — footprint and rework notes
The LM3S9B81-IBZ80-C5T is supplied in a 108-LFBGA package (10x10 mm body) with a 0.8 mm ball pitch typical of this density. Surface-mount only. For rework, the part is MSL 3 — a pre-bake at 125°C for 24 hours is mandatory if the moisture-barrier bag has been open beyond the floor-life window. The 1.235 V to 1.365 V core supply is tighter than the usual 3.3 V rail — a dedicated LDO or switching regulator for the 1.3 V core is needed, not a simple resistor divider.