Patent ID: 8842402

Claim:
A protection circuit device for at least one direct current (DC) source coupled to an electrical load, the protection circuit device comprising: a controller; a power switching metal-oxide-semiconductor field-effect transistor (MOSFET) having conduction terminals to be coupled to the at least one DC source, and a gate terminal to be coupled to an output of said controller; a comparator; a first voltage booster; a second voltage booster configured to boost a MOSFET voltage difference from said conduction terminals of said power switching MOSFET during a by-pass condition in the at least one DC source and to supply said comparator for enabling said first voltage booster; said first voltage booster configured to be coupled to said gate terminal of said power switching MOSFET for keeping said power switching MOSFET in a conduction mode while the MOSFET voltage difference is sensed by said comparator; said second voltage booster being configured to turn off when the MOSFET voltage difference reaches a voltage threshold, a supply voltage to said comparator and to said first voltage booster being based upon said first voltage booster; said controller comprising a control logic circuit having a first input configured to be coupled to an output of said comparator, a second input configured to receive a disable command signal, a first output configured to be coupled to an enable input of said first voltage booster, and a second output, a four terminal path inversion switch configured to receive the MOSFET voltage difference, to invert a sign of the MOSFET voltage difference input to said first voltage booster, and to operate based upon the second output of said control logic circuit, a supply voltage line configured to power said control logic circuit when the MOSFET voltage difference is not inverted, a sensor configured to be coupled to the second input of said control logic circuit, to generate the disable command signal, and to force said power switching MOSFET into the conduction mode, and an external command terminal configured to be coupled to the second input of said control logic circuit, to receive the disable command signal, and to force said power switching MOSFET into the conduction mode.