초록 ▼

A circuit having reverse battery protection includes a combination of an electrical load and an N-channel MOSFET inversely coupled in series with the load. The gate of the MOSFET is coupled to the high potential side of the electrical load. The series combination is powered by a DC voltage source. P

A circuit having reverse battery protection includes a combination of an electrical load and an N-channel MOSFET inversely coupled in series with the load. The gate of the MOSFET is coupled to the high potential side of the electrical load. The series combination is powered by a DC voltage source. Positive polarity voltages enhance the MOSFET and provide for low loss conduction thus completing the series circuit whereas negative polarity voltages bias the MOSFET off thus providing a DC block by way of the intrinsic diode of the inversely coupled MOSFET. Gate to source voltage may be limited or controlled to prevent damage due to punch through effects at high positive voltages and to ensure turn-off of the MOSFET at negative polarity voltages.

대표청구항 ▼

[ We claim:] [1.] A circuit including an electrical load normally powered by voltage of a first polarity across a pair of circuit terminals, said circuit effective for preventing current flow through the electrical load caused by voltage of a second polarity opposite the first polarity across the pa

[ We claim:] [1.] A circuit including an electrical load normally powered by voltage of a first polarity across a pair of circuit terminals, said circuit effective for preventing current flow through the electrical load caused by voltage of a second polarity opposite the first polarity across the pair of circuit terminals, the improvement comprising:said electrical load having high and low potential terminals, said high potential terminal coupled to the one of the pair of circuit terminals at a higher potential than the other of the pair of circuit terminals when voltage of the first polarity is across the pair of circuit terminals; and,a first N-channel MOSFET having a source coupled to the low potential terminal of the electrical load, a gate coupled to the high potential terminal of the electrical load, and a drain coupled to the one of the pair of circuit terminals at a lower potential than the other of the pair of circuit terminals when voltage of the first polarity is across the pair of circuit terminals.