| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify the circuit configuration of an amplifier circuit used for a light receiving element circuit and to reduce power consumption. <P>SOLUTION: A negative phase reference voltage generation circuit 30 generates the negative phase side reference voltage Vref2 of a differential output circuit S1 from a power supply voltage Vcc supplied from the outside and a reference voltage Vref1. A positive phase output amplifier circuit A1 outputs the positive phase side reference voltage Vref1 when the output signal of a photoelectric conversion circuit I1 is supplied to a non-inverted input terminal, the reference voltage Vref1 is supplied to an inverted terminal as a positive phase side reference voltage and a photodetector P1 is not irradiated with light. A negative phase output amplifier circuit A2 outputs a specified voltage Vpr higher than the positive phase side reference voltage Vref1 when the output signal of the photoelectric conversion circuit I1 is supplied to an inverted input terminal, the negative phase reference voltage Vref2 is supplied to a non-inverted terminal and the photodetector P1 is not irradiated with light. <P>COPYRIGHT: (C)2007,JPO&INPIT |
