Protection circuit
AssigneeMotorola, Inc.
InventorLloyd P. Matthews
Life of this patent
Estimating the term…
Abstract
A protection circuit (13) for an integrated circuit (10) is capable of handling higher externally-provided voltages supplied to internal circuitry within the integrated circuit (10). The protection circuit (13) comprises a zener diode (20), wherein a N+ type diffusion region (38) is separated from a P field implant (40) lying between the N+ type diffusion region (38) and a P+ type diffusion region (39).
Claims16
A circuit operable for protecting a protected device in an integrated circuit from energy having a voltage greater than a breakdown voltage of said protected device, said circuit comprising a semiconductor diode, wherein P and N portions of said diode are formed in a substrate and are separated by a portion of said substrate and a more highly doped portion of said substrate, a first terminal of said semiconductor diode coupled to an input pin of said integrated circuit and a second terminal of said semiconductor diode coupled to ground, wherein said semiconductor diode is coupled to said protected device, and wherein said semiconductor diode and said protected device have a substantially similar breakdown voltage.
A semiconductor diode comprising:
- a P well;
- an N type region formed in said P well for forming a first terminal of said semiconductor diode;
- a P type region formed in said P well for forming a second terminal of said semiconductor diode;
- and
- a more highly doped portion of said P well residing between said N type region and said P type region, wherein said more highly doped portion is separated from said N type region by a portion of said P well.
An integrated circuit comprising:
- circuitry requiring a voltage provided externally to said integrated circuit;
- and
- a protection circuit for protecting said circuitry from an electrostatic discharge voltage, said protection circuit comprising a diode coupled to an input pin of said integrated circuit, wherein said diode having P and N portions formed in a substrate and separated by a portion of said substrate and a more highly doped portion of said substrate, a first terminal of said diode coupled to said input pin of said integrated circuit and a second terminal of said diode coupled to ground, and wherein said diode and said circuitry have substantially similar breakdown voltages.
Dependencies are inferred from the claim text.