ESD diode structure
AssigneeKoninklijke Phillips Electronics N.V.
InventorsRoy A. Colclaser, David M. Szmyd
Life of this patent
Estimating the term…
Abstract
An ESD diode protects a circuit against electrostatic discharge (ESD). The ESD diode has four adjacent regions. The first and third regions are formed by doping a semiconductor substrate so that it has a P-type conductivity. The second and fourth regions are formed by doping the semiconductor substrate so that it has an N-type conductivity. The first region is for connection to a signal terminal of the circuit being protected when the fourth region is connected to a positive power line of the circuit. The fourth region is for connection to the signal terminal when the first region is connected to the ground line or a negative power line of the circuit.
Claims16
A device for protecting a circuit against electrostatic discharge having four adjacent regions, said device comprising:
- terminals consisting of only a first terminal and a second terminal;
- a first region and a third region formed from a semiconductor substrate having a p-type conductivity;
- a second region and a fourth region formed from said semiconductor substrate having an n-type conductivity;
- and
- a resistor connected between said third region and said first terminal, said resistor being external to said device;
- wherein said first region is connected to a signal terminal of said circuit when said fourth region is connected to a positive power line of said circuit, and wherein said fourth region is connected to said signal terminal when said first region is connected to one of a ground line and a negative power line of said circuit;
- said device shunting the electrostatic discharge away from said circuit.
A two terminal device for protecting a circuit against electrostatic discharge comprising:
- four regions of a semiconductor substrate, wherein a conductivity type of said four regions alternate between p-type and n-type;
- terminals consisting of only an anode and a cathode;
- a first region of said four regions being connected to said anode and a fourth region of said four regions being connected to said cathode, said first region and a third region of said four regions being of said p-type;
- and
- a resistor connected between said first region and said third region located between said fourth region and a second region, said resistor being external to said two terminal device;
- wherein said anode is connected to a signal terminal of said circuit when said cathode is connected to a positive power line of said circuit, and wherein said cathode is connected to said signal terminal when said anode is connected to one of a ground line and a negative power line of said circuit;
- said two terminal device shunting the electrostatic discharge away from said circuit.
A protected circuit arrangement comprising:
- a circuit having an input terminal and an output terminal, said circuit being connected to a first power line for providing a positive voltage and a second power line for providing one of a negative voltage and ground;
- a plurality of protection devices for protecting said circuit against electrostatic discharge, each of said plurality of protection devices having terminals;
- a first region and a third region formed from a semiconductor substrate having a p-type conductivity;
- a second region and a fourth region formed from said semiconductor substrate having an n-type conductivity;
- and a resistor connected between said third region and said anode, said resistor being external to said plurality of protection devices;
- wherein a first region of a first protection device of said plurality of protection devices and a fourth region of a second protection device of said plurality of protection devices are connected to said input terminal;
- and wherein a fourth region of said first protection device is connected to said first power line, and a first region of said second protection device is connected to said second power line;
- said protection devices shunting the electrostatic discharge away from said circuit.
Dependencies are inferred from the claim text.