LUPA-4000 Datasheet, PDF (18/49 Pages) Cypress Semiconductor – 4M Pixel CMOS Image Sensor

LUPA-4000
Data Sheet
time
Figure 9. Principle of non-destructive readout.
Essentially an active pixel array is read multiple times, and reset only once. The
external system intelligence takes care of the interpretation of the data. Table 7
summarizes the advantages and disadvantages of non-destructive readout.
Table 7: Advantages and disadvantages of non-destructive readout.
Advantages
Low noise – as it is true CDS.
High sensitivity – as the conversion
capacitance is kept rather low.
High dynamic range – as the results
includes signal for short and long
integrations times.
Disadvantages
System memory required to record the
reset level and the intermediate samples.
Requires multiples readings of each pixel,
thus higher data throughput.
Requires system level digital calculations.
3.9 Operation and signalling
One can distinguish the different signals into different groups:
• Power supplies and grounds
• Biasing and Analog signals
• Pixel array signals
• Digital signals
• Test signals
3.9.1 Power supplies and ground
Every module on chip, as there are: column amplifiers, output stages, digital modules,
drivers… has its own power supply and ground. Off chip the grounds can be
combined, but not all power supplies may be combined. This results in several
different power supplies, but this is required to reduce electrical cross-talk and to
improve shielding, dynamic range and output swing.
On chip we have the ground lines of every module which are kept separately to
improve shielding and electrical cross talk between them.
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Contact: [e-mail] Document #: 38-05712 Rev.**(Revision 1.2 )
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