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:
Aug. 16, 2005
Filed:
Jul. 30, 2002
Darin James Douma, Monrovia, CA (US);
Philip D. Shapiro, Palo Alto, CA (US);
Linda Xiaorong Liu, San Jose, CA (US);
Darin James Douma, Monrovia, CA (US);
Philip D. Shapiro, Palo Alto, CA (US);
Linda Xiaorong Liu, San Jose, CA (US);
Finisar Corporation, Sunnyvale, CA (US);
Abstract
The method and apparatus for monitoring a photo-detector generates a highly compliant mirror current across a broad range of photo-detector current levels. The apparatus for monitoring includes: a pair of bipolar transistors and a first non-linear isolation element. The pair of transistors are connected in a mirror configuration with a sense transistor one of the pair of transistors sensing a photo-detector current and with a mirror transistor one of the pair of transistors mirroring the photo-detector current with a mirror current. The first non-linear isolation element has at least two terminals a first of which couples to the collector of the mirror transistor. The first non-linear isolation element exhibits a non-linear voltage drop between the at least two terminals in response to varying levels of the mirror current to improve compliance between the mirror current and the detector current. Methods and means for monitoring a photo-detector are also disclosed.