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:
Sep. 02, 2014
Filed:
Jun. 10, 2010
Da-wei Lai, Hsinchu, TW;
Jen-chou Tseng, Jhudong Township, TW;
Chien-yuan Lee, Zhubei, TW;
Abstract
A latch-up prevention structure and method for ultra-small high voltage tolerant cell is provided. In one embodiment, the integrated circuit includes an input and/or output pad, a floating high-voltage n-well (HVNW) connected to the input and/or output pad through a P+ in the floating HVNW and also connected to a first voltage supply, a low-voltage n-well (LVNW) connected to a second voltage supply through a N+ in the LVNW, a HVNW control circuit, and a guard-ring HVNW, where the first voltage supply has higher voltage level than the second voltage supply, guard-ring HVNW is inserted in between the floating HVNW and LVNW to prevent a latch-up path between a P+ in HVNW and N+ in LVNW by using the HVNW control circuit that controls the guard-ring HVNW's voltage level. The guard-ring HVNW's voltage level is matched by the floating HVNW's voltage level.