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. 06, 2006
Filed:
Dec. 20, 2002
Pekka Ojala, Fremont, CA (US);
Pekka Ojala, Fremont, CA (US);
Exar Corporation, Fremont, CA (US);
Abstract
A double well structure beneath an inductor to isolate it from the substrate. Contacts are provided for the deeper well and the substrate, to reverse bias the junction between the substrate and the deep well. In one embodiment, for a P-substrate, the deep well is an N-well, and the other well is a P-well. Both the N-well junction with the substrate, and the junction between the N-well and the P-well are reverse biased. This improves the quality factor of the inductor structure above the wells by reducing eddy currents. In one embodiment, the P-well is striped. The deeper N-well extends upward into the gaps between the stripes. The stripes will further reduce the amount of eddy current by adding a reverse biased sidewall junction to the eddy current path, further helping to increase the quality factor of the inductor.