The LM3S6420-IBZ25-A2: This combination made it a fit for networked industrial controllers, building automation gateways, and remote terminal units where a single-chip Ethernet node was needed without an external PHY interface chip.
Because the part is obsolete, any incoming stock should be inspected for date-code consistency and marking integrity; the BGA package can be reballed if needed, but the laser-etched marking on the package top is the first authenticity check.
108-BGA package — footprint and handling notes
The LM3S6420-IBZ25-A2 comes in a 108-ball BGA (10x10 mm body), surface-mount only. The ball pitch is standard for this density, but the small footprint means the PCB land pattern must match the supplier device package exactly — no fudging the solder-mask opening. If the original stencil design was for this part, a replacement unit should drop in with the same reflow profile. For any surplus stock coming through the independent channel, check the moisture sensitivity level (MSL) on the bag label; if the seal is broken or the humidity card reads above the threshold, a bake before reflow is mandatory to avoid popcorning.