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:
Oct. 01, 2013
Filed:
Jul. 04, 2008
Ralf Hying, Munich, DE;
Ralf Hying, Munich, DE;
OSRAM Gesellschaft mit beschraenkter Haftung, Munich, DE;
Abstract
A circuit configuration may include an operational amplifier having a plus and a minus input and an output; and a current sensing resistor, whereby the voltage drop across the resistor is coupled to the minus input; a first transistor having a control electrode, a reference electrode and a working electrode, the working-reference electrode path of which is coupled in series to a first and second connection for a first LED between a connection for a supply voltage and the reference potential; a second transistor having a control electrode, a reference electrode and a working electrode, the working-reference electrode path of which is coupled in series to a first and second connection for a second LED between a connection for a supply voltage and the reference potential; a first switch and a second switch coupled in series between the output and the control electrode of the first and second transistor, respectively.