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. 14, 2021
Filed:
Feb. 19, 2020
Minoru Kado, Hachioji, JP;
Takumi Hyugaji, Isehara, JP;
Takeshi Sato, Yokohama, JP;
MITSUMI ELECTRIC CO., LTD., Tokyo, JP;
Abstract
Disclosed is a switching power supply device including: a transformer for voltage conversion; a main switching element connected in series to a primary coil; a primary side control circuit that performs on/off control of the main switching element; a synchronous rectification MOS transistor connected in series to a secondary coil; and a secondary side control circuit that performs on/off control of the MOS transistor, wherein the secondary side control circuit includes: an off-timing detection circuit that compares a drain voltage of the MOS transistor with a predetermined threshold voltage, and detects a timing to turn off the MOS transistor; and a threshold voltage setting circuit that sets the threshold voltage, and the threshold voltage setting circuit sets the threshold voltage based on a conduction period of the secondary coil or a period obtained by adding the conduction period to a conduction period of the primary coil.