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. 08, 2001
Filed:
Jun. 23, 2000
Bruce B. Roesner, San Diego, CA (US);
Single Chip Systems, San Diego, CA (US);
Abstract
Overload protection is provided to the tuned receiving front end circuitry of an RFID tag by selectively detuning the tuned receiving front end in response to sensed voltage overload generated across the tuned receiving front end by a high field. The tuned receiving front end is or is modeled as a tuned parallel inductor and capacitor tank circuit. A parallel capacitance is added to the tank circuit by means of a control transistor which is controlled by a voltage sensing circuit. The voltage sensing circuit senses the voltage being applied across the tank circuit and turns on the control transistor to a degree to sufficiently detune the tank circuit so that the operating voltage across the tank circuit remains at or below a desired operating value or safe limit regardless of the value of the field in which the RFID tag is placed.