Latch-up free RC-based NMOS ESD power clamp in HV use

摘要

An RC-based electrostatic discharge protection device provides an extended snapback trigger voltage range, thereby avoiding latch-up. Two parallel current discharge paths are provided between supply terminals during an electrostatic discharge event by virtue of an added external resistor. The first current discharge path includes body resistance of the protection device and the second current discharge path includes the external resistor.

主权项

1. A device comprising:
a protection circuit for a plurality of voltage supply terminals, the protection circuit comprising: a resistor and a capacitor connected in series across a pair of the supply terminals; an NMOSFET having a gate coupled by a body resistance to one of the supply terminals; an external resistor connected in series with the NMOSFET across the supply terminals; wherein: the gate of the NMOSFET is coupled to a junction between the resistor and capacitor; a plurality of diodes is connected in series between the gate of the NMOSFET and the junction; and a first diode is connected at its input to the junction and its output is coupled to a junction between the NMOSFET and the external resistor.