| CPC H03K 17/0822 (2013.01) [G05F 1/569 (2013.01); H02H 9/025 (2013.01)] | 20 Claims |
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1. A power system comprising:
a field effect transistor (FET) with a first terminal, a gate terminal, and a third terminal, wherein the first terminal, gate terminal, and third terminal are configured to control electrical current passing between the first terminal and the third terminal based on a voltage of the gate terminal;
a Zener diode connected in series between a first node and a second node, wherein the first node is connected to the first terminal of the FET and the second node is connected to the gate terminal of the FET, wherein the Zener diode is oriented to allow current through the Zener diode from the first node to the second node only if a voltage difference between the first and second nodes is at or over a Zener voltage of the Zener diode;
a diode connected in series between the Zener diode and the second node, wherein the diode is oriented to allow current from the first node to the second node and to inhibit current from the second node to the first node; and
a capacitor connected in parallel with both the Zener diode and the diode between the first and second nodes, wherein the capacitor is configured to raise a gate drive current of the FET during a rising edge of a lightning transient and thereby reduce a voltage drop across the FET faster than the Zener diode is able to do on its own;
wherein the capacitor is configured to reduce a total amount of energy that the FET must dissipate by 29% or more relative to if the capacitor was not coupled in parallel with the Zener diode.
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