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:
Oct. 26, 2010
Filed:
Jun. 19, 2008
Masaki Tagome, Osaka, JP;
Masaki Tagome, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A gate voltage detecting circuitdetects a gate voltage Vgs of a switching device, and when the gate voltage is less than a predetermined voltage that is set to be less than a threshold voltage of the switching device, outputs an H-level boost instruction signal. A voltage control circuit, when the boost instruction signal is at the L level, outputs a predetermined voltage Vof a control power supplyas it is, and when the boost instruction signal is at the H level, outputs a voltage Vobtained by boosting the predetermined voltage V. The drive signal output circuitamplifies a voltage of a PWM pulse output from a PWM pulse output circuitto a voltage output from the voltage control circuit. Therefore, a drive signal from the drive signal output circuitto the switching deviceinitially becomes the boosted voltage Vwhen the PWM pulse goes to the H level, and then becomes the predetermined voltage Vwhen the gate voltage Vgs of the switching deviceincreases to a predetermined voltage. Therefore, a switching loss of the switching device can be suppressed.