초록 ▼

The present invention discloses a circuit and method for detecting a fault current in a circuit containing a power transistor. A comparator in communication with a parasitic inductance is utilized to sense the excessive change in current through the power transistor. When the voltage magnitude throu

The present invention discloses a circuit and method for detecting a fault current in a circuit containing a power transistor. A comparator in communication with a parasitic inductance is utilized to sense the excessive change in current through the power transistor. When the voltage magnitude through the parasitic inductor exceeds a predefined limit, the comparator triggers a gate drive circuit. The gate drive circuit is in communication with the power transistor. The gate drive circuit shuts off the power transistor when the predefined limit is reached. Thus, the present invention is capable of reacting quickly to fault currents through the power transistor thereby protecting the transistor and other circuit components from damage.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for protecting a power transistor from being damaged by a fault current, the method comprising:providing an inductor in series with the power transistor;detecting voltage generated by the inductor in response to a change in current through the power transistor

[ What is claimed is:] [1.]1. A method for protecting a power transistor from being damaged by a fault current, the method comprising:providing an inductor in series with the power transistor;detecting voltage generated by the inductor in response to a change in current through the power transistor and the inductor, wherein the inductor voltage varies proportionally to the change in current through the power transistor and the inductor; andshutting down conduction of the power transistor when the magnitude of the inductor voltage exceeds a threshold voltage value indicative of a fault current.