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

摘要

A transimpedance amplifier (112) for converting a current signal output by a light receiving element (111) into a voltage signal has a variable current-voltage conversion gain. A gain control circuit (114) detects a bottom voltage of the voltage signal output by the transimpedance amplifier (112) and controls the conversion gain of the transimpedance amplifier (112) on the basis of the detection result. A convergence determination circuit (115) determines whether the gain control is in a state of convergence or a state of nonconvergence and outputs a determination signal indicating the determination result to the gain control circuit (114). When the determination signal indicates a shift from a nonconvergence state to a convergence state, the convergence control circuit (114) holds the conversion gain value at the time of the shift.