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. 24, 1991
Filed:
Jan. 22, 1991
Alberto Bilotti, Florida, AR;
Jose L Tallarico, Buenos Aires, AR;
Allegro Microsystems, Inc., Worcester, MA (US);
Abstract
A bipolar chopping driver circuit has a pair of NPN totem-pole connected driver transistors with a fly-back diode connected across the NPN source transistor and a biasing resistor connected between base and emitter of the source transistor. A fullwave bridge driver may be comprised of two such totem pole circuits with the inductive load connected between them at the junctions between NPN source and sink transistors. A clamp circuit is provided in both cases, for preventing the voltage swings at the bases of the source transistors from exceeding the DC supply voltage that is connected to the collectors of the source transistors, thereby permitting operation at high chopping frequencies without excessive delay in switching load current and excessive power losses.