Slow Turn-Off Optimization of CMOS ESD NAND Clamp to Eliminate Fly-Back Damage During Unlatch

The unlatching mechanism of the ESD NAND clamp can cause it to turn off sharply, resulting in fly-back and damaging oscillations. This paper presents simulations and hardware measurements which verify that a simple feedback circuit addition to the clamp can be effectively used to control the turn off and prevent failures.