OPTICAL RECEPTION CIRCUIT

摘要

An optical reception circuit includes a first photodetector, a first transimpedance amplifier, a level shift circuit, a second photodetector, a second transimpedance amplifier, a peak hold circuit, and a comparator. The first transimpedance amplifier converts a first light current from the first photodetector to a first voltage. The level shift circuit generates a signal voltage from the first voltage. The second transimpedance amplifier converts the second light current from the second photodetector to a second voltage. The peak hold circuit holds a peak voltage of the second voltage as a first threshold voltage. The comparator compares the signal voltage with the first threshold voltage.

主权项

1. An optical reception circuit comprising:
a first photodetector that receives a light signal and converts the light signal to a first light current; a first transimpedance amplifier that is connected to the first photodetector and converts the first light current to a first voltage; a level shift circuit that is connected to the first transimpedance amplifier and generates a signal voltage that is the first voltage shifted to a low-voltage side; a second photodetector that receives the light signal and converts the light signal to a second light current; a second transimpedance amplifier that is connected to the second photodetector and converts the second light current to a second voltage that is higher than a minimum voltage of the signal voltage and lower than a maximum voltage of the signal voltage; a peak hold circuit that is connected to the second transimpedance amplifier and holds a peak voltage of the second voltage as a first threshold voltage; and a comparator that is connected to the level shift circuit and the peak hold circuit and compares the signal voltage with the first threshold voltage.