C11440-10C Ver.1.2
9. DESCRIPTION OF VARIOUS FUNCTIONS
9-1 THEORY OF CMOS IMAGE SENSOR
The pixel of a CMOS image sensor is composed of the photodiode and the amplifier that
converts the charge into voltage. The entering light is converted into charge and converted
into voltage in the pixel. The voltage of each pixel is output by switching the switch one by
one. (Figure 9-1)
FL-280 that the scientific CMOS image sensor used in this camera has an on-chip CDS
(correlated double sampling) circuit, which plays an important role in achieving low noise. In
addition, FL-280 realizes both low noise and high speed readout simultaneously, owing to 1
line parallel simultaneous readout using column A/D.
Digital data out
CDS
CDS
CDS
A/D
A/D
A/D
Amp
Figure 9-1
Structure of the FL-280
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