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:
Dec. 05, 2017
Filed:
Aug. 01, 2013
Renesas Electronics Corporation, Tokyo, JP;
Norisato Takeya, Tokyo, JP;
Masashi Oshiba, Tokyo, JP;
Satoshi Kumaki, Tokyo, JP;
Yasutaka Horikoshi, Tokyo, JP;
Renesas Electronics Corporation, Tokyo, JE;
Abstract
The switching power source device obtains a desired DC voltage by controlling the current flowing through a coil by turning on and off a switching element by a PWM control. In the PWM ON period to turn on the switching element by the PWM control, the switching power source device is enabled to switch the switching element by a first pulse signal whose cycle is shorter than the PWM cycle and whose pulse width is gradually increased, in a first period just after the start of the PWM ON period. Further, the switching power source device is enabled to switch the switching element by a PWM signal based on the PWM control after the first period in the PWM ON period has elapsed. According to this approach, it is possible to reduce the harmonic noise.