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:
Apr. 21, 2009
Filed:
May. 15, 2007
Masahiro Nagata, Tokyo, JP;
Masahiro Nagata, Tokyo, JP;
Advantest Corporation, Tokyo, JP;
Abstract
There is provided a measurement circuit including a main amplifier that generates a direct voltage in accordance with an input voltage and applies the generated voltage to a device under test, a feedback element that feeds back the direct voltage to the main amplifier and controls the direct voltage generated from the main amplifier to a voltage according to the input voltage, a current detecting circuit that outputs a detecting voltage according to a current value of the direct current, and a clamping circuit that restricts the current value of the direct current output from the main amplifier, in which the clamping circuit includes a first limiting-voltage output section that outputs a limiting voltage according to a limiting value of the direct current, a first bias generating section that generates a bias voltage making use of the input voltage as a reference voltage based on a magnitude relation between the limiting voltage and the detecting voltage, and a limiting-current supplying element that is provided between a connecting point between the main amplifier and the feedback element and the first bias generating section and supplies a limiting current restricting the direct current to the device under test via the feedback element in accordance with a voltage difference between a voltage in the connecting point and the bias voltage.