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:
Nov. 04, 2008
Filed:
Nov. 08, 2006
Massimiliano Frulio, Milan, IT;
Stefano Surico, Milan, IT;
Andrea Sacco, Alessandria, IT;
Davide Manfre, Pandino, IT;
Massimiliano Frulio, Milan, IT;
Stefano Surico, Milan, IT;
Andrea Sacco, Alessandria, IT;
Davide Manfre, Pandino, IT;
Atmel Corporation, San Jose, CA (US);
Abstract
A plurality of memory sub-arrays are formed in a p-well region. Each of the memory sub-arrays has at least one first-level column decoder that includes a plurality of low-voltage MOS selector transistors that are also formed within the p-well. A last-level decoder is formed outside of the p-well region and includes high-voltage MOS transistors to provide an output signal to one of an array of sense amplifiers. During a memory erase mode of operation, a high voltage is provided to bias the p-well region and a plurality of high-voltage switches are activated to provide a high voltage to gate terminals of the selector transistor in the first-level column decoders. One or more intermediate-level column decoders are formed as low-voltage selector transistors in the p-well between the first-level column decoder and the last-level column decoder. Each of the intermediate-level column decoders also has a high-voltage switch that is activated during a memory erase mode of operation to provide a high voltage to gate terminals of the intermediate-level column decoders.