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:
Dec. 24, 2013
Filed:
Dec. 09, 2011
Bradley Jensen, San Jose, CA (US);
Charles Y. Chu, Cupertino, CA (US);
Bradley Jensen, San Jose, CA (US);
Charles Y. Chu, Cupertino, CA (US);
Altera Corporation, San Jose, CA (US);
Abstract
Integrated circuits with guard rings are provided. Integrated circuits may include internal circuitry that is sensitive to external noise sources. A guard ring may surround the functional circuitry to isolate the circuitry from the noise sources. The guard ring may include first, second, and third regions. The first and third regions may include p-wells. The second region may include an n-well. Stripes of diffusion regions may be formed at the surface of a substrate in the three regions. Areas in the guard ring that are not occupied by the diffusion regions are occupied by shallow trench isolation (STI) structures. Stripes of dummy structures may be formed over respective STI structures and may not overlap the diffusion regions. The diffusion regions in the first and third regions may be biased to a ground voltage. The diffusion regions in the second section may be biased to a positive power supply voltage.