| 摘要 |
<P>PROBLEM TO BE SOLVED: To actualize a light receiving circuit which can obtain a property high in dynamic range of an incident light power without addition of a gain control circuit. <P>SOLUTION: The light receiving circuit has: a photoelectric conversion device 11 which converts an incident light from the outside into an electric signal; and a differential amplifier 12 into a first input terminal of which an electric signal is input, into a second input terminal of which a reference signal is input, and which amplifies the potential difference between the electric signal and the reference signal. An input stage of the differential amplifier 12 has: an NMOS 14 into a gate terminal of which the electric signal from the photoelectric conversion device 11 is input, and an back gate of which is connected to GND; an NMOS 15 into a gate terminal G of which the reference signal is input, and a source terminal S of which is connected to GND together with a source terminal of the NMOS 14 via a constant current source 17; and a photoelectric conversion device 18 which is connected between a back gate B of the NMOS 15 and GND to receive a part of the incident light. <P>COPYRIGHT: (C)2008,JPO&INPIT |
