Fast turn-on protection of a cascode switch
AssigneePower Integrations, Inc.
InventorRajko Duvnjak
Life of this patent
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Abstract
Fast turn-on protection of a cascode switch is presented herein. A cascode circuit includes a depletion mode field effect transistor and an enhancement mode field effect transistor electrically coupled in cascode. During turn-on, a protection circuit detects an overcurrent fault by observing a plateau of a cascode node voltage. An overcurrent fault may be detected in response to the plateau existing for greater than a threshold time duration.
Claims20
A power converter comprising:
- a cascode circuit including a depletion mode field effect transistor and an enhancement mode field effect transistor electrically coupled in cascode, the cascode circuit configured to provide a cascode node voltage;
- and
- an overcurrent detection circuit configured to detect a period when the cascode node voltage gradually decreases and to indicate an overcurrent fault when the period exceeds a threshold time duration.
A method of detecting overcurrent in a gallium nitride (GaN) cascode circuit comprising:
- turning on the GaN cascode circuit with a transient step;
- receiving a cascode node voltage;
- determining a period when the cascode node voltage gradually decreases;
- and
- indicating an overcurrent fault in response to the period existing for greater than a threshold time duration.
A method of rapidly detecting overcurrent in a power converter comprising:
- turning on a cascode switch with a transient step;
- receiving a cascode node voltage;
- determining a period when the cascode node voltage gradually decreases;
- and
- indicating an overcurrent fault in response to the period existing for greater than a threshold time duration.
Dependencies are inferred from the claim text.