| 摘要 |
PURPOSE:To prevent malfunction from being generated even when an input signal is the one like a negative power source voltage and to decrease an offset voltage, by constituting a current mirror receiving a differential circuit of a PNP transistor, an NPN transistor, and a resistor. CONSTITUTION:Differential input terminals 11a and 11b are connected to the bases of the PNP transistors 1a and 1b, respectively, and the differential circuit is constituted of the transistors 1a and 1b. In the current mirror, the resistors 4a and 4b are inserted in a feedback loop constituted by the PNP transistors 3a and 3b and the NPN transistors 2a and 2b, and it is possible to decrease the collector potential of the NPN transistor 2a or 2b which becomes reference less than base potential. In such a way, an output circuit can output a signal without saturating the PNP transistors 1a and 1b which constitutes the differential circuit even when the input signal decreases to the negative power source voltage level.
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