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:
Jan. 07, 2003
Filed:
Feb. 21, 2002
Akihiko Ono, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
There is intended to provide a current-voltage converter capable of surely outputting a voltage output signal regardless of current intensity when converting a current input signal with wide current range into a voltage output signal. In case a current value of a current input signal Iin is small, small current regions of diodes D and D are used and current values of first bias currents IB and IB are set small. Thereby, the small current regions can be used as a region to deal with a large change rate of voltage against current and there can be obtained an effective voltage change even for a micro current. In case a current value of the current input signal Iin is large, current values of bias currents IB and IB at a constant current circuit increase to a second bias current to obtain a characteristic such that conversion voltage VM and reference voltage VP are compressed against the current input signal Iin. To obtain the compression characteristics, there is made used of a characteristic of the diodes D and D such that their terminal-to-terminal voltage against current increases monotonously forming a convex shape. Thereby, output voltage can keep compressed differential voltage in a wide current range. Accordingly, a differential amplifier circuit AMP does not need to change its dynamic range.