| 摘要 |
A controllable integrator for a bipolar integrated filter includes a voltage-current-transformer, a current distribution multiplier and an integrating amplifier. The voltage-current-transformer includes two transistors having their emitters connected via a converting resistor and two current sources each connected to a respective one of the emitters of the two transistors. The current distribution amplifier includes two logarithmic diodes each connected to a respective one of the collectors of the two transistors, a differential stage having differential inputs connected to the two logarithmic diodes, a controllable current source for supplying current to the differential stage, and a current mirror having an output and comprising two transistors of one conductivity type having emitters connected to a source of supply voltage and collectors connected to the output of the differential stage. The integrating amplifier includes an inverting amplifier having an input circuit including an input transistor of the one conductivity type, the input transistor having a base connected to the output of the current mirror and an emitter connected to the same source of supply voltage.
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