| 摘要 |
<p>An ignition system including a semiconductor chip which has a high withstand voltage and is constructed so as to cause a large current to flow between a first terminal and a second terminal, and on which is formed a power transistor having a high input impedance at a control terminal. The chip includes a protection circuit mounted thereon and composed of a power-supply circuit for receiving an input voltage supplied between the control terminal and the first terminal when the power transistor is set in an ON state so as to form a stabilized voltage and a control circuit for comparing a reference voltage formed on the basis of a constant voltage supplied by the power-supply circuit with a voltage corresponding to a current flowing through the power transistor so as to control the input voltage supplied to an input control terminal of the power transistor so that the current flowing through the power transistor does not exceed an allowable current.</p> |
