CURRENT-VOLTAGE CONVERSION CIRCUIT, OPTICAL RECEIVER, AND OPTICAL TERMINATOR

摘要

A trans-impedance amplifier that converts a current signal output by a light-receiving element into a voltage signal has a conversion gain that is variable. A gain control circuit detects a bottom voltage with respect to the voltage signal output by the trans-impedance amplifier and controls the conversion gain of the trans-impedance amplifier based on the detection results. A convergence determination circuit determines whether the control of gain is in a convergent state or a non-convergent and outputs to the gain control circuit a determination signal indicating the determination results. When the determination signal indicates a transition from the non-convergent state to the convergent state, the convergence control circuit maintains a value of the conversion gain at a time of the transition.

主权项

1. A current-to-voltage conversion circuit, comprising:
a trans-impedance amplifier to convert a current signal into a voltage signal, the trans-impedance amplifier having a conversion gain that is variable; a gain control circuit to detect a bottom voltage of the voltage signal output by the trans-impedance amplifier, and to control the conversion gain of the trans-impedance amplifier based on detection of the bottom voltage; and a convergence determination circuit to determine whether the gain control circuit is in a convergent state or a non-convergent state, and to output to the gain control circuit a determination signal indicating the determined state, wherein when the determination signal indicates a transition from the non-convergent state to the convergent state, the gain control circuit is to maintain a value of the conversion gain at a time of the transition.