Method for protecting a controllable semiconductor switch from overload and short-circuiting in a load circuit
AssigneeConti Temic microelectronic GmbH
InventorsUli Joos, Alexander Pölzer, Martin Speckner, Norbert Stuhler
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Abstract
A method for protecting a controllable semiconductor switch from overload and short-circuiting in a load circuit, the method—including detecting an output voltage of the semiconductor switch;—comparing a detected output voltage with a predicted switching progress; and—deactivating the semiconductor switch if the detected output voltage is lower than the predicted switching progress.
Claims12
A method for the protection of a controllable semiconductor switch against overload and short-circuiting in a load circuit, wherein the method comprises:
- detecting an input voltage of the semiconductor switch;
- detecting an output voltage of the semiconductor switch;
- computing, by a comparator, a difference between the detected output voltage and the detected input voltage;
- comparing, by a comparison circuit including an AND logic gate, the difference to a predicted switching progress computed by a controller that indicates a predicted output voltage at a specified time based on a predetermined characteristic curve of the semiconductor switch;
- triggering, by the controller, a control signal to activate the semiconductor switch in response to the AND logic gate indicating that the difference accords with the predicted switching progress;
- and
- triggering, by the controller, the control signal to deactivate the semiconductor switch in response to the AND logic gate indicating that the difference does not accord with the predicted switching progress.
A protective circuit for a controllable semiconductor switch against overload and short-circuiting in a load circuit, the protective circuit comprising:
- a monitoring circuit for detecting an input voltage of the semiconductor switch and detecting an output voltage of the semiconductor switch;
- at least one comparator for computing a difference between the detected output voltage and the detected input voltage;
- and
- a controller for:
- comparing, by a comparison circuit including an AND logic gate, the difference to a predicted switching progress that indicates a predicted output voltage at a specified time based on a predetermined characteristic curve of the semiconductor switch,
- triggering a control signal to activate the semiconductor switch in response to the AND logic gate indicating that the difference accords with the predicted switching progress, and
- triggering the control signal to deactivate the semiconductor switch in response to the AND logic gate indicating that the difference does not accord with the predicted switching progress.
Dependencies are inferred from the claim text.