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. 31, 2009
Filed:
Oct. 04, 2005
James C. Marshall, Puyallup, WA (US);
James C. Marshall, Puyallup, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
Circuitry for reliably regulating the current driving a laser diode or other current-driven load is described. In particular, a dual-current driver circuit is described that uses both a current source circuit and a current sink circuit. The current source circuit and the current sink circuit may each independently control the laser diode drive current within a desired operating tolerance. The current driving the laser diode will be maintained within tolerance despite the failure of either the current source circuit or the current sink circuit. This is because the current source circuit and the current sink circuit are combined with the laser diode in series, such that the current driving the laser diode will be controlled at the lower of the two currents driven by the current source circuit and the current sink circuit.