The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 2015
Filed:
Aug. 24, 2007
Jens Schneider, Munich, DE;
Klaus Roeschlau, Munich, DE;
Harald Gossner, Riemerling, DE;
Infineon Technologies AG, Neubiberg, DE;
Abstract
The invention relates to an ESD protection circuit for an integrated circuit including a drain-extended MOS device and an output pad that requires protection. The ESD protection circuit includes a first diode coupled to the output pad and to a bias voltage rail, a second diode coupled to the output pad and to another bias voltage rail, and an ESD power clamp coupled between the two bias voltage rails. The ESD power clamp is formed as a vertical npn transistor with its base and emitter coupled together. The collector of the npn transistor is formed using an n-well implantation and a DEMOS n-drain extension to produce a snapback-based voltage limiting characteristic. The diodes are formed with a lightly p-doped substrate region over a buried n-type layer, and a p-well implant and an n-well implant separated by intervening substrate. A third diode may be coupled between the two bias voltage rails.