| 摘要 |
PROBLEM TO BE SOLVED: To switch the connection of a pull-down resistor in a configuration using no separate power supply.SOLUTION: A pull-down resistive element 3 and a pnp transistor 4 (PNP switch 1) are connected between a gate terminal and a source terminal of a power MOSFET 2, and are controlled through a pnp transistor 8 (PNP switch 2) driven by a test control circuit 10. During a normal operation of the power MOSFET 2, the resistive element 3 is made effective so as to function as a pull-down resistor, and during a leak inspection, the resistive element 3 is made ineffective so as to control the gate terminal G into a high impedance state. Switching control of the resistive element 3 is performed without requiring a high voltage power supply nor a negative power supply. |
