Power circuit switching device having a passive protection circuit

[0029]FIG. 1 shows a switching device 1 according to the disclosure. A load P and a generator G of a power circuit connected to two switching terminals 2a, 2b of the device 1 are shown in dotted lines in this figure.

[0030]The generator G can have a high voltage, for example, 600V or more, and the current flowing in the power circuit and in the switching device 1 can be of high intensity, for example, above 1 A. The switching device 1, as is well known per se, selectively applies the generator G voltage to the load P. It therefore acts as a power switch, controlled by a relatively small switching signal of the order of a few volts.

[0031]The switching device 1 has a first terminal 3 for receiving this switching signal. This first terminal 3 is electrically connected via a driver circuit 4 to a gate of a high-voltage depletion mode transistor 5.

[0032]“High-voltage transistor” means a transistor comprising a drain, a source and a gate, the low amplitude voltage applied to the gate (of t...