The invention relates to a photovoltaic
detector read-out unit circuit applying an inverted
voltage follower. The photovoltaic
detector read-out unit circuit comprises a
cascade current mirror circuit, a current integrating circuit and a bias
voltage generating circuit, wherein transistors (Mp1 and Mp3) and transistors (Mp2 and Mp4) form the
cascade current mirror circuit; transistors (Mp2, Mp4 and Mn2) and an integrating
capacitor (Cint) form the current integrating circuit; and transistors (MBn1, MBn2, MBp1 and MBp2) form the bias
voltage generating circuit. According to the circuit, an
amplifier is not needed, the
power loss is low, lower
input resistance is realized and is unrelated to current of a
detector, and the constant injection efficiency can be realized; bias voltage of the detector can be controlled accurately, and constant bias voltage of the detector can be provided; current
gain of the read-out unit circuit can be changed through a dimension ratio of the transistors of a
current mirror; a
background current deduction circuit can be conveniently added,
background suppression is realized, and the
dynamic range of the circuit is enlarged; and the
dynamic range is large, and input light current higher than bias current can be processed.