| 摘要 |
PURPOSE:To attain current mirror operation at a low input voltage by providing a constant voltage element connected between the base and collector of the 1st transistor (TR), the 1st constant current circuit connected to a constant voltage element and the 2nd constant current circuit connected to a collector of the 2nd TR. CONSTITUTION:When no input signal is fed to an input terminal 15, a collector current of the 2nd TR7 is made equal to a collector current I2 of the 1st TR6 by the current mirror effect and all the output current I2 of the 2nd constant current circuit 13 flows to the collector of the 2nd TR7. Then when an input current I3 flows to the input terminal 15, the collector voltage of the 1st TR6 is equal to a voltage at no signal, the collector current of the 2nd TR7 is I2+I3 and the current I3 flows to an output terminal 16. A leading voltage VDS of a Schottky diode 8 is nearly 0.4V, the voltage at the input terminal 15 is nearly 0.2V and the current mirror circuit is activated by a low input voltage.
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