Light receiving amplification circuit

摘要

A light receiving amplification circuit according to the present invention includes: a light receiving element; an amplification circuit which amplifies a photoelectric current generated by the light receiving element and outputs from an amplification stage for external output and a plurality of amplification stages for feedback; an operating current source set in each of the amplification stages which supplies an operating current to the corresponding amplification stages; a gain selection switch set in the respective plurality of amplification stages for feedback, which interrupts the operating current between the corresponding amplification stage and the operating current source; and a gain resistor set in the respective plurality of amplification stages for feedback and connected between the operating current side of the corresponding gain selection switch and an input of the amplification circuit.