Abstract: The reverse breakdown voltage of a conventional insulated gate transistor is greatly increased by the addition of a lightly doped layer between the substrate and a buffer layer of the insulated gate transistor. The addition of the lightly doped layer does not increase the on resistance of the device, nor the cut-off time of the device. The lightly doped layer can be provided as an epitaxial layer along with the other epitaxial layers of the insulated gate transistor.

Abstract: An improved semiconductor AC switch is described having internal bias generation for the power MOSFET switches and isolated control input. Dual power MOSFETS with substrate diodes are connected in series between source and load. DC gate bias for the MOSFETS is derived from an internal power supply containing energy storage which charges from the line, typically every half cycle. The gates of the power MOSFETS are tied to the internal bias generator through a voltage divider network containing a variable resistance controlled by an optical input signal. The internal energy storage may be a capacitor or solid state battery, preferably a monolithic thick or thin film battery. No transformers or external control bias generators are required and the resulting switch is particularly simple and compact.

Abstract: MOSFET devices or circuits incorporating an improved substrate temperature sensing element are obtained by forming a PN junction directly on a thin (gate) dielectric region. The temperature sense junction is desirably formed in a poly layer. By mounting it directly on thin (gate) dielectric its thermal response to temperature changes in the substrate is improved while still being electrically isolated from the substrate. It is desirable to provide over-voltage protection elements coupled to the junction to avoid rupture of the underlying thin dielectric. Because the sense diode and all the over-voltage protection devices may be made of poly with junctions perpendicular to the substrate, the structure is particularly compact and simple to fabricate.

Abstract: MOSFET devices or circuits incorporating an improved substrate temperature sensing element are obtained by forming a PN junction directly on a thin (gate) dielectric region. The temperature sense junction is desirably formed in a poly layer. By mounting it directly on thin (gate) dielectric its thermal response to temperature changes in the substrate is improved while still being electrically isolated from the substrate. It is desirable to provide over-voltage protection elements coupled to the junction to avoid rupture of the underlying thin dielectric. Because the sense diode and all the over-voltage protection devices may be made of poly with junctions perpendicular to the substrate, the structure is particularly compact and simple to fabricate.

Abstract: An improved semiconductor AC switch is described having internal bias generation for the power MOSFET switches and isolated control input. Dual power MOSFETS with substrate diodes are connected in series between source and load. DC gate bias for the MOSFETS is derived from an internal power supply containing energy storage which charges from the line, typically every half cycle. The gates of the power MOSFETS are tied to the internal bias generator through a voltage divider network containing a variable resistance controlled by an optical input signal. The internal energy storage may be a capacitor or solid state battery, preferably a monolithic thick or thin film battery. No transformers or external control bias generators are required and the resulting switch is particularly simple and compact.

Abstract: A semiconductor current regulating and switching apparatus is described wherein an NMOS enhancement mode power transistor is used in the positive lead to regulate the flow of current from a power source to a load. In order to achieve a low resistance on-state for the NMOS power transistor, the control gate must be biased to a voltage which exceeds the positive voltage of the power source. This bias voltage is generated within the apparatus.