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. 25, 2008
Filed:
May. 25, 2006
Yoshiaki Hachiya, Otsu, JP;
Ryutaro Arakawa, Amagasaki, JP;
Minoru Fukui, Takatsuki, JP;
Takashi Kunimatsu, Takatsuki, JP;
Yoshiaki Hachiya, Otsu, JP;
Ryutaro Arakawa, Amagasaki, JP;
Minoru Fukui, Takatsuki, JP;
Takashi Kunimatsu, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The peak current flowing to the switching device drops in a no-load state with PWM control, but because the number of switching operations is constant regardless of the load, further reducing power consumption is difficult. The switching power supply device has a PWM signal generator for generating a PWM signal, a switching device Qfor switching the first supply voltage VIN based on the PWM signal, converters for outputting the difference between a second supply voltage and a reference voltage as a difference signal, and an intermittent oscillation control circuit for stopping the switching operation of the first switching device when the difference signal is less than a predetermined first threshold value (Vp). The PWM signal generator changes the pulse width based on the difference signal to generate the PWM signal.