CYIL1SM1300AA_09 Datasheet, PDF (10/29 Pages) Cypress Semiconductor – LUPA-1300 1.3 MPxl High Speed CMOS Image Sensor

CYIL1SM1300AA
Figure 9. Integration and Readout in Parallel
Read frame I
Read frame I + 1
Integration I + 1
Integration I + 2
The control of the readout of the frame and of the integration time are independent of each other with the only exception that the end
of the integration time from frame I+1 is the beginning of the readout of frame I+1.
Non-Destructive Readout (NDR)
The sensor can also be read out in a non-destructive way. After a pixel is initially reset, it can be read multiple times, without resetting.
The initial reset level and all intermediate signals can be recorded. High light levels will saturate the pixels quickly, but a useful signal
is obtained from the early samples. For low light levels, one has to use the later or latest samples.
Figure 10. Principle of Non-Destructive Readout
time
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 6 summarizes the advantages
and disadvantages of non-destructive readout.
Operation and Signaling
One can distinguish the different signals into different groups:
■ Power supplies and grounds
Table 6. Advantages and Disadvantages of Non-Destructive
Readout
Advantages
Disadvantages
Low noise – as it is true CDS. System memory required to
record the reset level and the
intermediate samples.
High sensitivity – as the
Requires multiples readings of
conversion capacitance is kept each pixel, thus higher data
rather low.
throughput.
High dynamic range – as the Requires system level digital
results include signal for short calculations.
and long integrations times.
■ Biasing and analog signals
■ Pixel array signals
■ Digital signals
■ Test signals
Power Supplies and Grounds
Every module on chip, as there are: column readout, 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 power
supplies, but is required to reduce electrical crosstalk and to
improve shielding.
On chip we have the ground lines also separately for every
module to improve shielding and electrical crosstalk between
them. The only special ground is "Gnd_res", which can be used
to remove the blooming if any and which can improve optical
crosstalk.
An overview of the supplies is given in Table 7. The power
supplies related to the pixel array signals are described in the
paragraph concerning the pixel array signals.
Note
9. Normal application does not require this Gnd_res and it can be connected to ground.
Document Number: 38-05711 Rev. *D
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