Patent ID: 6885249

Claim:
An optical signal receiving circuit, comprising: a first transimpedance amplifier configured to convert a first current signal into a first voltage signal, wherein the first current signal is generated in a first photodiode, to which an optical signal is inputted; a reference voltage generating circuit configured to generate a second voltage signal which is independent of the first voltage signal and which is a signal of a reference voltage; a level shift circuit configured to shift at least one of the first voltage signal and the second voltage signal in a close direction and output it, wherein the close direction is a direction in which the center voltage of the amplitude of the first voltage signal and the voltage of the second voltage signal get closer, wherein the amplitude of the first voltage signal is generated based on a result of detection of light of the optical signal in the first photodiode; and a differential amplifier to which the first voltage signal and the second voltage signal outputted from the level shift circuit are inputted, the differential amplifier configured to amplify a difference between the first voltage signal and the second voltage signal.