METHOD FOR CHECKING THE SWITCH-OFF CAPABILITY OF A MOSFET
Disclosed is a method for checking the turn-off capability of an electronic fuse in the form of a MOSFET, said electronic fuse being used as an interrupter switch between a voltage supply and a control device, wherein the MOSFET is turned on during operation as intended and is operated in the linear region, wherein, for checking the turn-off capability, the gate-source voltage of the MOSFET is reduced by a predefined value until a predefined threshold value is reached and, after the threshold value has been reached, the gate-source voltage is increased again to the previous value for turning on the MOSFET, and wherein a check is made to ascertain whether the drain-source voltage of the MOSFET increases as the gate-source voltage is reduced.
1 . A method for checking the turn-off capability of an electronic fuse in the form of a MOSFET, said electronic fuse being used as an interrupter switch between a voltage supply and a control device, comprising:
turning on the MOSFET during operation as intended,
operating the MOSFET in the linear region,
reducing the gate-source voltage of the MOSFET by a predefined value until a predefined threshold value is reached,
after the threshold value has been reached, increasing the gate-source voltage to a previous value for turning on the MOSFET, and
ascertaining whether the drain-source voltage of the MOSFET increases as the gate-source voltage is reduced.
2 . The method as claimed in claim 1 , wherein the MOSFET is controlled and checked by a control and diagnosis circuit controlled by a control unit.
3 . The method as claimed in claim 1 , wherein the gate-source voltage is reduced in time ranges in which the control device does not have a high current demand.
4 . The method as claimed in claim 2 , wherein the gate-source voltage is reduced in time ranges in which the control device does not have a high current demand.