| 摘要 |
PROBLEM TO BE SOLVED: To provide a protection circuit that is hard to be broken by a surge voltage.SOLUTION: A protection circuit 2 includes: an N-channel MOS transistor Q connected between an external terminal 1 and a line of a ground voltage VSS; a resistive element R1 and a capacitor C1 connected in series between the external terminal 1 and a gate of the transistor Q; a resistive element R2 connected between the gate of the transistor Q and the line of the ground voltage VSS; and a capacitor C2 connected between the external terminal 1 and the gate of the transistor Q. The capacitor C2 includes two electrodes E3 and E4 provided so as to face each other. The capacitor C2 is harder to be broken by a surge voltage than the capacitor C1 formed by the gate and a diffusion layer of the MOS transistor. |
