Patent ID: 7161264

Claim:
A semiconductor device comprising: an embedded insulation layer formed in a semiconductor substrate; a plurality of power semiconductor transistors formed on said semiconductor substrate; a trench isolating between said plurality of power semiconductor transistors formed on said semiconductor substrate on said embedded insulation layer, whereby said plurality of power semiconductor transistors are individually isolated from each other and, isolated from any other semiconductor transistors; an isolator insulating and driving control electrodes of said power semiconductor transistors and including capacitive coupling provided for transmitting signals between said plurality of power semiconductors transistors; wherein at least two of said plurality of power semiconductor transistors are each connected to each other in series; and a drive circuit for driving a control electrode of each of said power semiconductor transistors to suppress driving current supplied to one of said at least two power semiconductor transistors when over current is detected in current flowing in at least another one of said at least two power semiconductor transistors connected in series, wherein said plurality of power semiconductor transistors drive an ignition coil.