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:
Nov. 02, 1999
Filed:
Aug. 25, 1997
Michael R Feldman, Charlotte, NC (US);
John Childers, Concord, NC (US);
Fouad Kiamilev, Charlotte, NC (US);
Digital Optics Corporation, Charlotte, NC (US);
Abstract
A laser diode power controller, and method, are disclosed. The controller can be implemented entirely in CMOS technology due to the simplicity of its quasi-decision-based control routines. The control routines involve the use of a window comparator which determines whether the measured power level of a laser diode falls within a desired range of values. The simplified control routines are also manifested by the use of digital registers to set the desired current values that are to be output to the laser diode and monitor diode. The modulation current supplied to the laser diode exhibits much lower noise levels because the modulation digital to analog converter (DAC) By supplying a continuous current that is selectively switched between the laser diode and a dummy load, much less noise is induced in the power supply than if it had to respond to large changes in modulation current, i.e., OFF (zero) and ON (desired Imod).