| 摘要 |
A surge protection circuit comprises a surge detection circuit 14 for detecting a surge applied to a semiconductor integrated circuit, and a protection element 15 for absorbing the surge. The protection element is connected between a signal terminal for supplying a signal to the semiconductor integrated circuit and a power source terminal for supplying a power source voltage. When the power source voltage is not larger than a voltage enough to normally operate the semiconductor integrated circuit and the surge detection circuit does not detect the surge, the protection element is set in a current limiting state. When the power source voltage is not larger than a voltage enough to normally operate the semiconductor integrated circuit and the surge detection circuit detects the surge, the protection element is set in a current non-limiting state. |
