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:
Mar. 03, 2015
Filed:
Jun. 27, 2012
Toshimitsu Nakai, Tokyo, JP;
Toshimitsu Nakai, Tokyo, JP;
Mitsubishi Electric Corporation, Chiyoda-Ku, Tokyo, JP;
Abstract
A logarithmic conversion circuit comprises: an operation amplifier; an input resistor connected at a preceding stage of an inverting input terminal, of the operation amplifier, to which a current signal is inputted; and a logarithmic conversion device and a current feedback device connected in series between the inverting input terminal and an output terminal of the operation amplifier, and an inverse-logarithmic conversion circuit comprises: a current/voltage conversion circuit which, after the current signal having passed through the current feedback device is inputted, converts the inputted current signal to a voltage value corresponding thereto; and a subtraction circuit outputting the difference between an output voltage of the current/voltage conversion circuit and a predetermined reference voltage, a circuit constant of the subtraction circuit being set such that the difference output of the subtraction circuit has a linearity proportional to the current signal.