| 摘要 |
PURPOSE:To prevent a reverse current from flowing even if a low voltage is applied to an input by adding a diode between emitters of a differential transistor (TR) so as to increase the dielectric strength when viewed from the input terminal of an input transistor. CONSTITUTION:A TRQ1 to the base of which an input signal VIN is inputted is connected to a common constant current source I1 via a diode D1 and a TRQ2 to the base of which a reference voltage Vref is given is connected to the I1 via a diode D2. When the input signal VIN is not given, the base potential of the TRQ1 approaches almost a minimum potential VEE of the circuit because of a pull-down resistor R3. The effect is ensured remarkably without deteriorating the performance of the circuit in using TRs having a low reverse dielectric strength of emitter-base in this way and the leakage current is eliminated, thereby improving the reliability. |
