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:
Feb. 23, 2016
Filed:
May. 07, 2012
Viet Hoang Nguyen, Leuven, BE;
Pascal Bancken, Opwijk, BE;
Viet Hoang Nguyen, Leuven, BE;
Pascal Bancken, Opwijk, BE;
NXP B.V., Eindhoven, NL;
Abstract
A method of characterizing an LED, as well as an integrated circuit using this method, based on a so-called characteristic resistance, in which the LED is operated at a first, relatively low, operating current and then at a second, relatively high, operating current. From the ratio between the difference between the forward voltages at these two operating currents, and the difference between the operating current, the characteristic resistance is determined. The characteristic resistance is measured at two or more moments during the operational lifetime of the device, and a prediction or estimate is made in relation to the total operational lifetime of the devices, from the evolution or change of the characteristic resistance.