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:
Sep. 21, 1999
Filed:
Aug. 11, 1997
Fujitsu Limited, Kawasaki, JP;
Abstract
The present invention discloses a signal amplifier circuit used in, for example, a receive portion in an optical communication system, and including an automatic threshold value setting portion to automatically set a threshold value depending upon a '1' side level and a '0' side level of an input signal, an automatic gain control amplifying portion to take as inputs the input signal and the threshold value from the automatic threshold value setting portion so as to perform differential amplification, and a gain control portion to detect amplitude information of the input signal so as to feed a gain control signal according to amplitude of the input signal to the automatic gain control amplifying portion as a feedforward signal. It is thereby possible to avoid limitation of a signal amplified in the signal amplifier circuit at a time of reproduction of a pulse signal, and compensate for offsets present in circuits so as to suppress a variation in pulse width of the output signal.