| 摘要 |
PURPOSE:To attain the suppression of a reverse base-emitter voltage with high general-purpose application, by connecting a base of the 3rd transistor(TR) to an emitter common connecting point of the 1st and the 2nd TRs, connecting the collector to a high potential power supply and connecting the emitter to a reference power supply. CONSTITUTION:A TRQ3 is provided, whose emitter is connected to a base of a TRQ1, whose base is connected to the emitter of the TRQ1 and whose collector is connected to a power supply VCC. When an input level VIN of an input terminal IN is decreased and a reverse base-emitter voltage of the TRQ1 is equal to a forward base-emitter voltage VF of the TRQ3, the TRQ3 turns on and an emitter current of the TRQ3 flows from the terminal IN through a current limit resistor RB1. Thus, the reverse base-emitter voltage of the TRQ1 does not exceed the VF. |
