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:
Mar. 25, 2003
Filed:
Mar. 30, 2001
Karl Richard Volk, Scotts Valley, CA (US);
Andrew J. Mrizek, San Jose, CA (US);
Gary Hurtz, Pleasanton, CA (US);
Maxim Integrated Products, Inc., Sunnyvale, CA (US);
Abstract
Current source methods and apparatus for light emitting diodes providing constant diode current and illumination in the presence of voltage and process variations. The method comprises providing a predetermined current through a first transistor, and mirroring the current through the first transistor to at least one additional transistor while holding the voltage across the first transistor to a predetermined value, wherein each additional transistor is coupled in series with a light emitting diode. An exemplary circuit, as well as various illustrative applications are disclosed.