Charge injection circuit.

摘要

A charge injection circuit for injecting a charge to a signal processing circuit has a photo-voltaic element (21, 91) for generating a photocurrent (IP) when an infrared light is received, a field effect transistor (22, 92) used for injecting the charge to the signal processing circuit, and an impedance conversion circuit (25, 93) for feeding back an output of the field effect transistor to a substrate potential of the photo-voltaic element. The impedance conversion circuit has a gain (A) which is less than or equal to one.