OPTICAL RECEPTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide an optical reception circuit that further reduces generation of a distortion in a pulse width of an output signal.SOLUTION: An optical reception circuit 10 includes a first voltage source 1, a second voltage source 2, a photodiode 3, a transimpedance amplifier 18, and an output circuit 20. The first voltage source 1, the second voltage source 2, and the transimpedance amplifier 18 are connected to the output circuit 20. The second voltage source 2 is connected to the transimpedance amplifier 18 such that an output voltage Va of the transimpedance amplifier 18 is input thereinto. The first voltage source 1 is so configured that a first threshold voltage Vth1 is a constant voltage and is higher than the output voltage Va in an initial state with no flow of photocurrent Ipd through the photodiode 3. The second voltage source 2 is so configured that a second threshold voltage Vth2 is lower than the output voltage Va in the initial state and changes more gradually than the output voltage Va as the output voltage Va changes.