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:
Jun. 09, 1998
Filed:
Dec. 09, 1996
Phillip R Luque, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A current steering circuit accomplishes high speed switching of drive current through a vertical cavity surface emitting laser (VCSEL) diode. The preferred embodiment of the current steering circuit includes a first and second schottky diode, connected anode to anode, as the circuit elements used to steer the current that flows into the common connection point of the schottky diodes. The cathode of the first schottky diode is connected to the anode of the VCSEL diode. The cathode of the second schottky diode is connected to one side of a network formed from three resistors. The other side of the network is connected to the output of a CMOS invertor used to buffer the video signal which controls the steering of the current. With the output of the CMOS invertor at a high level, the second schottky diode is in the off state and the first schottky diode is in the on state, forcing drive current to flow through the VCSEL diode. With the output of the CMOS invertor at a low level, the first schottky diode is in the off state and the second schottky diode is in the on state, forcing drive current to bypass the VCSEL diode.