Circuit for improving noise immunity by DV/DT boosting
AssigneeInternational Rectifier Corporation
InventorsMassimo Grasso, Muthu Subaramanian
Life of this patent
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Abstract
A circuit for suppressing false operation of a level shift circuit due to a noise transient, the circuit comprising a first transistor coupled to a voltage source of the level shift circuit and being coupled to pass a current when a noise transient is present on the voltage source an output terminal coupled to the first transistor providing as an injected signal a current proportional to the current in the first transistor to at least one level shift transistor of the level shift circuit to prevent false triggering of the level shift circuit due to the noise transient.
Claims24
A circuit for suppressing false operation of a level shift circuit due to a noise transient, the circuit comprising:
- a first transistor coupled to a voltage source of the level shift circuit and being coupled to pass a current when a noise transient is present on said voltage source;
- and
- an output terminal coupled to the first transistor providing as an injected signal a current proportional to said current in said first transistor to at least one level shift transistor of the level shift circuit to prevent false triggering of the level shift circuit due to the noise transient.
A circuit for suppressing false operation of a level shift circuit due to a noise transient, the circuit comprising:
- a first transistor having a control input coupled to a voltage source of the level shift circuit affected by the noise transient,
- a second transistor coupled in series with the first transistor and which simulates a parasitic capacitance of a transistor in the level shift circuit;
- a third transistor coupled to the first transistor as a current mirror for mirroring a current flowing in the first transistor;
- and
- an output terminal providing as an injected signal a current flowing in said third transistor mirroring the current in the first transistor and coupled to at least one level shift transistor in the level shift circuit to prevent false triggering of the level shift circuit due to the noise transient.
A method for suppressing false operation of a level shaft circuit due to a noise transient, the method comprising:
- providing a first transistor having a control input coupled to a voltage source of the level shift circuit affected by the noise transient and passing a current through the first transistor in response to the noise transient present on the voltage source;
- and
- providing an injection signal in response to said current in the first transistor to at least one level shift transistor of the level shift circuit to prevent false trigering of the level shift circuit due to the noise transient.
Dependencies are inferred from the claim text.