| 摘要 |
PURPOSE:To obtain a good-S/N and high-band photoelectric conversion electric signal characteristic by inserting a positive-phase amplifier of an approximately voltage gain 1 in parallel to a photo diode and outputting a synthesized voltage of this amplifier and a load resistance. CONSTITUTION:Positive-phase amplifier A of an approximately voltage gain 1 is inserted in parallel to photo diode iS, and a synthesized voltage of amplifier A and load resistance R is outputted. As the result, the input impedance of amplifier A can be large, and load resistance R can be made of a large value. Since the input capacity of amplifier A intself is in parallel with load resistance R, the influence of the input capacity can be reduced. Consequently, a good-S/N and high-band photoelectric conversion electric signal characteristic can be obtained. |
