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:
Oct. 04, 2011
Filed:
Jun. 11, 2009
Toshiyuki Imai, Oizumi-machi, JP;
Takahiro Iida, Oizumi-machi, JP;
Joji Noie, Ota, JP;
Sanyo Semiconductor Co., Ltd., Gunma, JP;
Semiconductor Components Industries, LLC, Phoenix, AZ (US);
Abstract
A motor drive circuit includes a first amplifier circuit to amplify a difference between first and second position detection signals with a gain becoming smaller according to drop in power supply voltage, to output a first amplification signal, the first and second position detection signals being signals indicating a rotational position of a rotor in a motor, having a frequency corresponding to a rotation speed of the motor, and being opposite in phase to each other; a second amplifier circuit to amplify the difference between the first and second position detection signals with the gain, to output a second amplification signal opposite in phase to the first amplification signal; and a drive circuit to amplify the difference between the first amplification signal and the second amplification signal with a predetermined gain to be saturated at the power supply voltage, to output a driving voltage for driving the motor.