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:
Jun. 23, 2020
Filed:
Oct. 30, 2018
Renesas Electronics Corporation, Tokyo, JP;
Satoshi Narumi, Tokyo, JP;
RENESAS ELECTRONICS CORPORATION, Tokyo, JP;
Abstract
To surely detect a back electromotive force generated in a non-conduction phase at an extremely low duty ratio, a motor driving system includes a three-phase motor, an inverter circuit, and a semiconductor device. A controller included in the semiconductor device compares a voltage at an output node corresponding to a non-conduction phase of the inverter circuit and a reference voltage with each other, thereby estimating a position of a rotor of the three-phase motor and generating a pulse width modulation signal based on the estimated position of the rotor. The controller detects the voltage at the output node of the non-conduction phase in a regeneration period of the pulse width modulation signal when a duty ratio of the pulse width modulation signal is less than a threshold value, the regeneration period being a period in which current is made to flow to the three-phase motor on a regeneration path.