MAX1636 is a synchronous buck switch mode power supply controller for laptop CPU’s. Taken from a Apple Clamshell iBook from 2000. Packaged in a 20 pin DIP with 2000 week 35 date code.
As well as a fairly large area for the die markings (And mask layer numbering.) Die code PW80Y that bears no relation to MAX1636.
In addition the die has a rather unusual marking. On the wide die seal (Conventionally tied to ground electrically) in one section the M1-M2 vias have been used to write CAEEFODS with a mirror image. Probably only 1 or 2 people have any idea what this was for 😉
Datasheet and Pin Out
There is a datasheet for the part. Switch Mode controllers are fairly complex circuits as can be seen from the block diagram in the datasheet.I’m not able to recognize any of the blocks but here is the pin out of the die