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:
Dec. 26, 1989
Filed:
Sep. 20, 1988
Serge Ramet, Grenoble, FR;
SGA-Thomson Microelectronics S.A., Gentilly, FR;
Abstract
A device for comparing currents comprises a first resistor (R1) connected between a high voltage source (VCC) and a connection node (N), first and second current source (I1, I2) connected between a low voltage source (VEE) and the connection node by first and second switches (S1, S2) closed during the first and second phases, a first differential amplifier (A1), a first input (-) of which is connected with the connection node by a first capacitor (C1), a second input (+) of which is connected with an intermediate voltage source, and the output of which is connected with the input (-) by a third switch (S3) closed during the first phase, a second resistor (R2) having a high value with respect to the first resistor connected between the connection node and the intermediate voltage source, and servo-control means operating during a phase preliminary to the first and second phases for urging the voltage on the connection node to be equal to the intermediate voltage, when the first switch is closed.