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. 17, 1986
Filed:
May. 31, 1985
Bernd Kalkhof, Reutlingen, DE;
Horst Lohmuller, Tubingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
In order limit the rate of rise of current when the final stage transistor T8 is switched, the base current of the final stage transistor is supplied by a first current-controlled current source when the final stage transistor switches on an inductive load. The final stage transistor in this circuit can be given an integrating behavior with a very small MOS negative feedback capacitor, leading to the control current input of the first controlled current source, to which a diode-connected switching transistor T4 supplies a constant current when a driver transistor T7 is blocked by an input signal U.sub.E. When the driver transistor T7 is made conducting, the constant current is diverted to the driver transistor and the base current of the final stage transistor T8 is cut off except for the dynamic contribution of feedback capacitor, while the reverse peak diode D provides protection against voltage spikes. A second current-controlled current source is inteposed between a constant current source and the diode-connected switching transistor in order to provide voltage decoupling between the constant current source and the switching transistor.