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. 08, 2003
Filed:
May. 16, 2002
Masahiro Tsuchida, Aichi-ken, JP;
Nobumasa Ueda, Nagoya, JP;
Hiroshi Fujimoto, Nagoya, JP;
Yoshiki Koyama, Okazaki, JP;
Denso Corporation, Kariya, JP;
Abstract
A current control circuit controls a gate potential of a transistor to equalize a load current IL with a trapezoidal wave signal Sb. The trapezoidal wave signal Sb increases at a constant gradient when a drive command signal Sa turns into H level. Due to increase of load current IL, the transistor starts operating in a linear region and a gate voltage VGS abruptly increases. A saturation state detecting circuit turns a current saturation signal Sc into L level when the gate voltage VGS exceeds a reference voltage Vr. A trapezoidal wave generating circuit stops increase of trapezoidal wave signal Sb. When drive command signal Sa turns into L level, the trapezoidal wave signal Sb decreases at a constant gradient. The load current IL decreases according to reduction of trapezoidal wave signal Sb.