Single-channel UART in a hermetic 28-CDIP
The P8251A is a single-channel UART (Universal Asynchronous Receiver/Transmitter) with full modem control, built as a programmable communications interface by AMD (Xilinx). Housed in a 28-pin ceramic DIP (28-CDIP) with through-hole mounting, this package provides hermetic sealing and high-reliability performance suited for military, aerospace, and industrial environments where board-level conformal coating or extreme temperature cycling is the norm.
Because it is a single-source active part without a direct pin-compatible second source from the original manufacturer, the closest functional peer is the N8251A — same UART core, same package, same supply range — but confirm the exact BOM position before swapping.