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. 14, 2005
Filed:
Jun. 14, 2002
Sau Ching Wong, Hillsborough, CA (US);
Sau Ching Wong, Hillsborough, CA (US);
Multi Level Memory Technology, Reno, NV (US);
Abstract
Auto-tracking bit line reference schemes generate a '½ cell current' reference by programming reference cells to threshold voltages that are between threshold voltage levels used to represent data. A common word line can control both a selected memory cell and a reference cell to provide a reference current, and differential sense amplifiers can compare a bit line current to reference currents to thereby distinguish data values. Current through other reference cells can be mirrored to pull-up devices to further improve the tracking of the reference line and bit line currents. Embodiments of the invention can be used with binary and multiple-bit-per-cell memories and with a variety of memory array architectures and memory cell structures.