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:
Dec. 05, 2000
Filed:
Nov. 09, 1998
Masaaki Maeda, Tokyo, JP;
Makoto Sudo, Nagoya, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
Circuitry capable of controlling a bias voltage for an avalanche photodiode (APD) in accordance with the temperature slope of the breakdown voltage of the APD is disclosed. A reference voltage generating circuit sets a voltage implementing an optimal amplification ratio on an output terminal, and generates a reference voltage by taking account of the temperature slope of the breakdown voltage of the APD. The reference voltage is applied to one input of a voltage comparator. A setting circuit feeds to an adding circuit a preselected voltage for controlling the voltage on the output terminal to a value capable of implementing the optimal multiplication ratio. A temperature compensating circuit feeds to the adding circuit a voltage corresponding to the temperature slope of the above breakdown voltage. The temperature slope is representative of the variation of the breakdown voltage with respect to temperature. The adding circuit adds the two input voltages and delivers its output to the voltage comparator as the reference voltage. The voltage comparator produces a difference between the reference voltage and a voltage input from the output terminal and outputs a voltage control signal representative of the difference.