Texas Instruments Incorporated
Ground fault current interrupter circuit

Abstract:

A ground fault current interrupter circuit includes a plurality of comparators, threshold generation circuitry, and a plurality of timer circuits. Each of the comparators is configured to compare a threshold voltage to a signal representative of a difference of current flow to a load and current flow from the load. The threshold generation circuitry is configured to generate a plurality of different threshold voltages. Each of the different threshold voltages is provided as the threshold voltage for one of the comparators. Each of the comparators is coupled to one of the timer circuits, and the one of the timer circuits is configured to activate a fault signal responsive to activation of an output of the comparator for a time that is related to the threshold voltage provided to the comparator. The time increases with lower values of the threshold voltage.