CYIS1SM0250-AA
Document Number: 38-05713 Rev. *B
Page 9 of 24
Sensor Architecture
Figure 6. STAR250 Schematic
The base line of the STAR250 sensor design consists of an
imager with a 512 by 512 array of active pixels at 25
µm pitch.
The detector contains on-chip correction for Fixed Pattern
Noise (FPN) in the column amplifiers, a programmable gain
output amplifier and a 10-bit Analog-to-Digital Converter
(ADC). Through additional preset registers the start position of
a window can be programmed to enable fast read out of only
part of the detector array.
Pixel Structure
The image sensor consists of several building blocks as
outlined in Figure 6. The central element is a 512 by 512 pixel
array with square pixels at 25
µm pitch. Unlike classical
designs, the pixels of this sensor contain four photodiodes.
This configuration enhances the MTF and reduces the PRNU.
Figure 7. shows an electrical diagram of the pixel structure.
The four photodiodes are connected in parallel to the reset
transistor (T1). Transistor T2 converts the charge, collected on
the photo diode node, to a voltage signal that is connected to
the column bus by T3. The Reset and the Read entrance of
the pixel are connected to one of the Y shift registers.
Figure 7. STAR250 Pixel Structure
9
10
D9...D0
Clk_ADC
Ain
S
R
Column Amplifiers
512
512
1024
1024
Ld_X
X Address
Decoder / Shift Register
Rst
Sig
Progr. Gain
Amplifier
Sync_YL
Clk_YL
Ld_Y
9
9
512
Pixel Array
512 by 512 Pixels
512
Rst
Sel
Col
Clk_YR
SyncYR
A8...A0
Aout
9
T1
T2
T3
Read
Reset
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