Abstract of the Disclosure

A monolithic semiconductor device is disclosed comprising a power switching thyristor and a temperature sensitive thyristor integrated on a common substrate. In preferred form, the temperature sensitive thyristor is electrically connected between the gate terminal and one of the main terminals of the power switching thyristor, and is thermally actuatable to intrinsically switch from a high to a low resistance state above a predetermined temperature of the power switching thyristor sensed through the common substrate, whereby to shunt gate current and automatically inhibit turn-on of the power switching thyristor to prevent overheating thereof. Depending on circuit variations, the power switching thyristor may be rendered conductive above or below a predetermined temperature, or within a defined temperature range. Normally off and normally on devices are disclosed.

• Figure 1 is a circuit diagram of the preferred embodiment of the present invention.
• Figure 2 is an enlarged cross-sectional view of a single chip of silicon showing the components of Figure 1 integrated therein to form an integrated circuit on a common substrate.

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