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:
Mar. 19, 2013
Filed:
Sep. 09, 2009
Yajun Wei, Sunnyvale, CA (US);
William D. Collins, Iii, San Jose, CA (US);
Daniel A. Steigerwald, Cupertino, CA (US);
Yajun Wei, Sunnyvale, CA (US);
William D. Collins, III, San Jose, CA (US);
Daniel A. Steigerwald, Cupertino, CA (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Philips Lumileds Lighting Company, LLC, San Jose, CA (US);
Abstract
A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the 'end' zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Qand Qn+1) effectively create back-to-back zener diodes across the two pins since the zener diodes share a common p+ substrate. The n+ regions of the end zener diodes Qand Qn+1 have the highest breakdown voltage requirement and must be placed relatively far apart. Adjacent n+ regions of the intermediate zener diodes have a much lower breakdown voltage requirement so may be located close together. The zener diodes may be placed within a very small footprint or can be larger for better suppressor performance.