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:
Jan. 12, 1988
Filed:
Feb. 18, 1986
David R Huffman, Westford, VT (US);
Scott C Lewis, Essex Junction, VT (US);
James E Rock, Milton, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An improved sense circuit for determining the data state of a memory cell in a multilevel storage system is disclosed. The sense circuit includes at least two differential voltage level sensing circuits. A first differential voltage level sensing circuit compares the relative magnitudes of a data input signal voltage level corresponding to a particular memory cell charge level and a first reference voltage level, thereby providing at least one first binary data output signal. The first binary data output signal is then used to generate a second reference voltage level having a magnitude different from that of the first reference voltage level. A second differential voltage sensing level circuit compares the relative magnitudes of an adjusted data input signal voltage level and a second reference voltage level, thereby providing at least one second binary data output signal. The adjusted data input signal corresponds to a function of the first data input signal. Hence, the binary data output signals provided correspond to the charge level stored in the memory cell.