| 摘要 |
PURPOSE:To prevent the destruction of a circuit element at the output side of a boosting circuit and the circuit element for limiting a voltage by limiting the level of the boosting voltage obtained from the electrode at an output side by applying an input voltage essentially level-limited to the electrode at the input side of a boosting capacity. CONSTITUTION:By using a pulse signal level-limited at an input side, a timing signal boosted to an electric power source voltage or above is generated. Namely, an MOSFETQ9 is provided between the input side electrode of a capacity Cp1 and the earth electric potential point of a circuit, a reference voltage VC is supplied through the N channel MOSFETQ7 of a diode mode to the gate of an MOSFETQ6, and at the gate of the MOSFETQ6, the N channel MOSFETQ8 of a diode mode to cause the electric current to be conducted toward a reference voltage VC is provided. Since the level of the pulse signal supplied to the input side electrode of a boosting capacity is limited, the level of the boosted output voltage obtained from the output side electrode can be limited and the destruction due to the high voltage of a circuit element provided at the output side can be prevented. |
