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. 21, 2002
Filed:
Sep. 08, 2000
Masahiro Kitagawa, Aichi-ken, JP;
Junichi Nagata, Aichi-ken, JP;
Denso Corporation, Kariya, JP;
Abstract
In the high side switch type of electrical load driving circuit, wherein an N channel MOS transistor is provided on the circuit for supplying power to the electrical load, a zener diode is provided between the drain and the source of the MOS transistor to protect the MOS transistor. A load is provided between the gate and the ground to protect the MOS transistor. In this circuit, when a positive high voltage is induced on the side of the electrical load, the zener and a parasitic diode of the MOS transistor flows forward currents which absorb the high voltage noise. When a negative high voltage noise is induced from the side of the electrical load, a breakdown current flows through the zener diode, so that the voltage difference between the drain and source is clamed to a predetermined voltage. Then, the diode turns on the MOS transistor. Thus, the MOS transistor can be surely protected from high voltage noises without increasing the current capacities of elements for the protection circuit.