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:
May. 07, 1996
Filed:
Oct. 27, 1994
Karl M Schlager, Campbell, CA (US);
Francesco Carobolante, Portola Valley, CA (US);
Solomon K Ng, Singapore, SG;
SGS-Thomson Microelectronics, Inc., Carrollton, TX (US);
Abstract
Circuitry for selectably connecting the body node of drive transistors of a motor control circuit. In particular, those transistors that are turned off when operating the motor in a unipolar mode have their body nodes switched so as to be connected to a reference voltage, such as ground, during unipolar mode, and to be connected to the transistor source during bipolar mode (i.e., when the transistors are active). The circuitry also is operable to briefly connect the body nodes of the transistors to their source when the opposing drive transistor is commutated, in the unipolar mode. In this way, forward biasing of inherent diodes in the drive transistor is avoided in unipolar mode, except when useful to clamp the inductive kick of the motor coils.