| 摘要 |
PURPOSE:To expand the dynamic range of circuit output and to utilize effectively the dynamic range by connecting a capacitor between output terminals of a differential amplifier and controlling its midpoint potential to a prescribed potential. CONSTITUTION:The capacitor 6 is connected between both the output terminals of the differential amplifier l and outputs of the output terminals are inputted to an adder 9 via buffer circuits 7,8 respectively. Thus, since an inverting output signal of the amplifier l is fed across the capacitor 6, the midpoint of the capacitor 6 is a ground point in terms of AC and the circuit shown in an equivalent in figure is obtained. Let the capacitance of the capacitor 6 be C, the combined capacitance of the apacitors 6A,6B is 2C. Thus, the dynamic range of the output led at the output terminal 10 is doubled. Further, a resistor addition circuit is connected between output terminals of the circuits 7,8, its output voltage is compared with a reference voltage by a midpoint control circuit so as to make the midpoint potential of the capacitor 6 equal to the midpoint potential of the dynamic range thereby utilizing the dynamic range effectively.
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