SEMICONDUCTOR DEVICE, CONTROL IC FOR SWITCHING POWER SUPPLY, AND SWITCHING POWER SUPPLY UNIT

摘要

Aspects of the invention can include a semiconductor device, control IC for switching power supply and switching power supply unit, which allow input voltage detecting function to be realized without resistor-voltage dividing circuit. An npn-type element consisting of p-type region, collector region and emitter region is included inside of drain region of starting element. On a first interlayer insulating film, aspects of the invention can provide collector electrode wiring of npn-type element, emitter-drain electrode wiring serving as both emitter electrode wiring of npn-type electrode and drain electrode wiring of starting element, source electrode wiring of starting element, and gate electrode wiring of starting element. A first metal wiring can serve both as input terminal of starting element and input terminal of npn-type element is connected to collector electrode wiring. The npn-type element can function as input voltage detecting means for detecting input voltage drop applied to the first wiring.

主权项

1. A semiconductor device comprising:
a field effect transistor having a drift region of a second conductivity type formed in a surface layer of a semiconductor substrate of a first conductivity type, and a drain region of a second conductivity type formed in a surface layer of the semiconductor substrate in contact with the drift region; a semiconductor region of a first conductivity type selectively formed in a surface layer of the drain region; a first semiconductor region of a second conductivity type selectively formed in a surface layer of the semiconductor region of the first conductivity type; a second semiconductor region of a second conductivity type selectively formed in the surface layer of the semiconductor region of the first conductivity type, apart from the first semiconductor region of the second conductivity type; a first electric wiring connected to the first semiconductor region of the second conductivity type, and externally inputted with an input voltage; and a second electric wiring connected to the drain region and the second semiconductor region of the second conductivity type.