Switching device with a power FET and an inductive load
US5936439A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | May 13, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/161
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A switching device with a power FET for switching an inductive load to which a free-wheeling diode is connected in parallel, wherein the terminal of the series resistor facing away from the gate terminal is connected to a driver circuit which is so designed that it connects the specified terminal with a reverse potential in order to block the FET, wherein, at the beginning of the process of making the FET conductive, it connects the specified terminal with a high resistance to a control voltage source that puts the FET into the conductive state, in such a way that the current rise of the current flowing through the FET is slowed down to such an extent that, within a period of time in which the free-wheeling diode is not yet blocking after starting to make the FET conductive, an increase of the current to undesirable high values is prevented, so that damage to the power FET and the free-wheeling diode and/or other circuit elements and/or the occurrence of electromagnetic disturbances is reduced, and wherein, after the point of time at which the free-wheeling diode has achieved its blocking capability, the specified terminal is connected by the driver circuit with low resistance to a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.