| 摘要 |
PURPOSE:To attain stable operation by connecting additionally an NPN and a PNP transistor(TR), and a resistor to an input terminal to limit a reverse voltage. CONSTITUTION:Since a base of the PNP TRQ2 is connected to a reference voltage Vbb when an input VIN is clamped to a voltage Vcc by connecting additionally the NPN TRQ1, the PNPTRQ2 and the resistor R1 to an input circuit, the emitter voltage is clamped to nearly -0.5V, and a reverse voltage applied between a base and an emitter of a TRQ4 which is in an off-state is almost zero. When the input VIN is clamped by a voltage VEE, since the base of the NPN TRQ1 is connected to the reference voltage Vbb, the emitter potential is clamped to nearly -2.1V, and the reverse voltage applied between the base and emitter of a TRQ3 is almost zero also. |
