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:
Feb. 22, 2000
Filed:
Jan. 07, 1999
Macronix International Co., Ltd., Hsinchu, TW;
Abstract
A method and apparatus for programming a non-volatile memory cell wherein the rate of current flowing through the cell is controlled via a current limiter coupled to the source node of the memory cell. The rate of current through the current limiter controls the programming current rate through the memory cell. The current limiter is controlled by an input which is dependant upon the setting of a current through an associated current mirror device. The current mirror current is controlled by a pre-defined input condition on a current source. The mirror current is used by a biasing circuit to generate a proportional input to the current limiter device. The current source thereby controls the current limiter rate. The current source can be formed from the same process as the memory cells and its output will thereby vary with the conductivity of the formed devices. This variation in the current source output, and hence the current limiter current, can be used to compensate for the comparable conductivity variations in the memory cells. The programming current rate can thereby be controlled, and can additionally be controlled according to process variations in the memory cell devices.