초록 ▼

Low voltage semiconductor devices are integrated monolithically with a high voltage semiconductor device on an electrically conductive substrate. The substrate forms an electrode of the high voltage device and is connected in use to the high voltage terminal of a power supply. The low voltage device

Low voltage semiconductor devices are integrated monolithically with a high voltage semiconductor device on an electrically conductive substrate. The substrate forms an electrode of the high voltage device and is connected in use to the high voltage terminal of a power supply. The low voltage devices operate from a regulated low voltage supply, which is regulated with reference to the high voltage supply voltage, and not with reference to ground. This reduces the need to isolate the low voltage devices from the conductive substrate. An intelligent power switch circuit constructed in accordance with the invention is suitable for use in automotive and lighting applications.

대표청구항 ▼

A power switching circuit suitable for controlling a load in an electrical system having a positive, high-voltage supply terminal and a negative common return terminal, the circuit being connected in operation between the high-voltage supply terminal and one terminal of the load, another terminal of

A power switching circuit suitable for controlling a load in an electrical system having a positive, high-voltage supply terminal and a negative common return terminal, the circuit being connected in operation between the high-voltage supply terminal and one terminal of the load, another terminal of the load being connected to the return terminal, the circuit comprising an electrically conductive semiconductor substrate carrying a high-voltage semiconductor output device in which conduction is predominantly by electrons, the substrate comprising a region of the output device for connection to the high-voltage supply terminal, the substrate also carrying at least one low-voltage semiconductor device forming part of a low-voltage circuit connected in operation to two low-voltage supply terminals, characterized in that the circuit further comprises means for eliminating the need for high-voltage isolation between the low-voltage device and the semiconductor substrate by maintaining each of the two low-voltage supply terminals at no more than a low and substantially constant voltage with respect to the positive high-voltage supply terminal.