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. 15, 2002
Filed:
May. 03, 2001
Petre Popescu, Kanata, CA;
Paul T. Banens, Kanata, CA;
Nortel Networks Limited, St. Laurent, CA;
Abstract
The invention relates to a driver circuitry suitable for controlling an operation of a laser or an optical modulator and providing extended dynamic range of the output power and enhanced quality of the output signal. It comprises a power control unit, a pre-driver stage and an output stage. The pre-driver stage and the output stage include differential amplifiers, the output stage amplifier preferably having a cascode configuration. The pre-driver stage provides a preliminary amplification of an input signal which is received and further amplified by the output stage. The power control unit operates in response to a reference signal, e.g. variable DC voltage or a feedback signal, and generates two control signals which control operating points of the pre-driver and the output stage in such a manner that higher output power of the driver corresponds to the higher output signal from the pre-driver stage. Conveniently, both the pre-driver stage and the output stage may be controlled by the same control signal. Depending on the product requirements, the driver circuit can be monolithically integrated with a device to be driven by the circuit.