| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical receiver equipment and optical receiver circuit with which an inputted optical signal can be normal received without generating the distortion of a waveform even when its level is high. SOLUTION: The equipment has a photodetector 2 for converting the optical signal into a current signal, current mirror circuit 3 for generating the same first and second current signals as the current signal converted by that photodetector 2, first preamplifier 4 having a high amplification factor for amplifying and converting the first current signal generated by the current mirror circuit 3 to a voltage signal, second preamplifier 5 having a low amplification factor rather than that of the first preamplifier 4 for amplifying and converting the second current signal generated by the current mirror circuit 3 to a voltage signal. The equipment has also a selector circuit 12 for selecting the first preamplifier 4 when no saturated area operation occurs at the first preamplifier 4, and selecting the second preamplifier 5 when the saturated area operation occurs at the first preamplifier 4, and changeover switch 13 for performing switching so as to output the voltage signal from the first preamplifier 4 or the second preamplifier 5 selected by the selector circuit 12. |
