| 摘要 |
PURPOSE:To obtain a broad band amplifier whose temperature drift is corrected by connecting the 2nd voltage current converting circuit having nearly the same temperature characteristic as that of the 1st voltage current converting circuit to the input of a current mirror circuit. CONSTITUTION:In impressing a voltage signal to an input terminal 300, it is converted into a current signal by a resistor 30, the signal is given to a transistor (TR) 40 connected to a diode of the current mirror circuit 4, and a current equal to the current flowing to the TR 40 flows to the connector of a TR 41 being an output of the circuit 4. Since the voltage at an input point of the circuit 4 is a voltage VBE similarly as that of the circuit 1, an output current Ic41 of the circuit 3 is expressed as Ic41=(V300-VBE)/R30, where V300 is a voltage impressed to a terminal 300 and R30 is a resistance value of the resistor 30. Thus, the temperature drift produced in the input current of the circuit 1 is corrected. Since the TR41 is constituted as a common emitter circuit, the TR 41 is not saturated and the range in the input voltage V30 is widened.
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