| 摘要 |
PURPOSE:To obtain a protective circuit, which can protect an internal circuit sufficiently even when the withstanding voltage of a gate oxide film is close to supply voltage and has long life, by forming a MOSFET, a drain thereof is connected to a power supply and a gate and a source thereof a re connected to an input resistor, and a second MOSFET, etc., a gate thereof is connected to the power supply. CONSTITUTION:An input protective circuit has an input resistor 7, first and second MOSFETs8, 9 having a first conduction type such as an N-channel type and a load element 10. With the first MOSFET8, a drain is connected to a power supply 1, and a gate and a source are connected in common and connected to an input terminal 3 through the input resistor 7. A gate is connected to the power supply 1 in the second MOSFET9. One end is connected to the power supply 1 in the load element 10. The gate and the drain in the first MOSFET8 are connected to the other end of the load element 10 through the second MOSFET9 while being connected to internal circuits 11, 12 for an integrated circuit. A MOSFET having a second conduction type such as a P- channel type is used as the load element 10, and a gate thereof is connected to a ground. |
