| 摘要 |
PURPOSE:To save power consumption by opening the base of PNP transistor used as an overvoltage breakdown preventive element. CONSTITUTION:The overvoltage breakdown preventive elements P1, P2, P3 and P4 are respectively connected between an input terminal I and power supply line VCC, between input terminal I and ground lead GND, between an output terminal O and power supply line VCC and between an output terminal O and ground lead GND. Each overvoltage breakdown preventive element is formed by a PNP transistor Q. The emitter thereof is connected to the terminal I or terminal O, while the collector to the power supply line VCC or the ground lead GND and the base is opened. |
