| 摘要 |
PURPOSE:To prevent breakdown due to the handling of a MOSIC, by turning a depletion type protective transistor OFF wherein the desired voltage is applied to a gate according to a condition that the MOSIC is used. CONSTITUTION:When operating a MOSIC by handling, a deplection type protective transistor 10 is under an ON condition because bias is not applied to a gate of said transistor. Thus, even if static electricity with high voltage generated during the handling of the MOSIC is input to an input terminal 1, charge is rapidly discharged to an earth line 11 through the deplection type protective transistor 10 under the ON condition. Consequently, an input transistor 4 is protected because high voltage is not applied to the input transistor. When practically employing the MOSIC, a DC-DC converter 12 is operated, the desired voltage is applied to the gate of the deplection type transistor 10 and the transistor 10 is brought to an OFF condition. |
