摘要 |
In a chip containing high-voltage device with a semiconductor substrate of a first conductivity type, a method of implementing low-voltage power supply is provided, wherein the electrical potential of an isolated region of a second conductivity type in a surface portion is used as one output terminal or as a voltage by which a transistor is controlled to provide output current for a low-voltage power supply. The other output terminal could be either terminal of the two that apply high voltage to high-voltage device or could be a floating terminal. Using this method, a low-voltage power supply can be implemented not only for the low-voltage integrated circuit (I) in a power IC containing one high-voltage device, but also for the low-voltage integrated circuit in a power IC having totem-pole connection or CMOS connection. As there is no need to implement depletion mode device in the chip, the fabrication cost is reduced.
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