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:
Nov. 01, 2005
Filed:
Jun. 12, 2002
Andrew T. K. Tang, Santa Clara, CA (US);
Andrew T. K. Tang, Santa Clara, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A current integration circuit includes an operational amplifier having a capacitor connected between its output and inverting input which integrates an input current. To prevent the op amp's output from becoming saturated, a charge dumping circuit dumps a known charge of the opposite polarity to that stored on the capacitor to the op amp's inverting input, thus reducing the charge on the capacitor and preventing the op amp's output from becoming saturated. A charge dump is triggered whenever the op amp's output exceeds a predetermined trip voltage. Counting the number of charge dumps performed during a given integration period provides a coarse indication of the magnitude of the integrated input current, and the output of the op amp provides a fine indication.