Replacing surface mount parts can look like a difficult or even impossible task. 

We were recently asked if we could find a replacement for an 80 pin PLCC part. 

This was an old programmable logic chip from Lattice. We found a modern part that had sufficient logic for the task and was smaller than the original.

Working with the original logic designs we re-wrote the logic using modern VHDL and then designed a suitable way of mounting this on to the original board.

This picture shows the original part on its board:

This picture is the new part:

The new part can be seen mounted onto a PCB made to the size of the original part.

It solders down onto the original pads. The new logic was programmed into chip and the board now works exactly as it did originally allowing product to continue for the foreseeable future.