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:
Oct. 20, 2009
Filed:
Mar. 21, 2007
Applicants:
Weiye LU, Sunnyvale, CA (US);
Elroy M. Lucero, San Jose, CA (US);
Khusrow Kiani, Oakland, CA (US);
Inventors:
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K 3/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In an I/O driver that includes a cascoded pair of PMOS driver transistors connected to a pair of cascaded NMOS driver transistors and that defines a pad output between the PMOS and NMOS driver transistors, a method of providing the CMOS I/O driver with over-voltage and back-drive protection includes providing circuitry for charging the wells of the PMOS transistors either to VDDIO during normal voltage mode by making use of the power supply, or to a common voltage during over-voltage and back-drive operation using the pad voltage.