March 28, 2013

NXP 7555 : Weekend die-shot

7555 is a CMOS version of 555 timer.

There are number of interesting things on the chip: see "unused" via's on the folded resistors at the top and at the center of the chip? They are here to trim resistance by modifying only 1 metal layer mask. Also, note large multifingered "power" transistors.