| 摘要 |
<P>PROBLEM TO BE SOLVED: To ensure, when a switch circuit formed by connecting in a cascade an NPN bipolar transistor and a MOS-FET is turned off, that the bipolar transistor goes reliably into a reverse bias state. <P>SOLUTION: The switch circuit is formed by connecting in a cascade a switch element Q1, that is an NPN bipolar transistor with a MOS-FET switching element Q2. A potential setting circuit is provided that ensures reverse bias state for the switching element Q1, when the switch circuit is OFF. The potential setting circuit is provided with a diode Dbe inserted between the emitter and the base of the switch element Q1, and a voltage source Vee, which is connected via a resistance Re to the anode side of the diode Dbe and which applies a prescribed DC potential thereto. <P>COPYRIGHT: (C)2003,JPO |
