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:
May. 04, 1999
Filed:
Sep. 30, 1997
Alan Kramer, Agrate Brianza, IT;
Roberto Canegallo, Tortona, IT;
Mauro Chinosi, Cologno Monzese, IT;
Giovanni Gozzini, Palazzolo Sull'oglio, IT;
Pier Luigi Rolandi, Volpedo, IT;
Marco Sabatini, Brescia, IT;
STMicroelectronics, S.r.l., Agrate Brianza (MI), IT;
Abstract
A programmable reference voltage source includes a nonvolatile memory cell, the floating-gate region of which stores electric charges determining a memorized threshold value. The drain terminal of the cell is biased at a constant voltage, and the source terminal is coupled to a constant-current source and to the inverting input of an operational amplifier having the noninverting input coupled to a reference voltage and the output coupled to the gate terminal of the cell. By defining the threshold of the cell as the gate voltage (measured with respect to ground) capable of causing the cell to be flown by the current set by the current source, the output voltage of the operational amplifier equals the threshold and may be used as a programmable reference in analog memories.