LUPA-1300 Datasheet, PDF (25/48 Pages) Cypress Semiconductor – 1.3 M Pixel High Speed CMOS Image Sensor

LUPA-1300
Datasheet
Vmemory, row select and Vpix. These are internal generated signals derived by on
chip drivers from external applied signals. Consequently it is important to understand
the relation between both internal and external signals and to understand the operation
of the pixel.
The timing of the pixel is given in figure 12 in which only the internal signals are
given.
Figure 12: Internal timing of the pixel.
At the end of the integration time, the information on the photodiode node needs to be
sampled and stored onto the pixel memory, required to allow synchronous shutter.
To do this, we need the signals “Precharge” and “Sample”. “Precharge” resets the
pixel memory and “Sample” places the pixel information onto the pixel memory.
Once this information stored, the readout of the pixel memories can start in parallel
with a new integration time. An additional signal “Vmem” is needed to obtain a
larger output swing.
Except from Vpix power supply, drivers generate the other pixel signals on chip. The
external signals to obtain the required pulses consist of 2 groups. One is the group of
digital signals to indicate when the pulse must occur and the other group is dc-supply
lines indicating the levels of the pulses. Table 9 summarizes the relation between the
internal and external pixel array signals
Internal
Vlow
Vhigh
External Low dc
High dc
signal
control
level
level
signal
Precharge
0
5V
Precharge
Gnd
Vddr
Sample
0
5V
Sample
Gnd
Vddr
Reset
0V
4 – 6V
Reset &
Gnd_res
Vres &
Reset_ds
Vres_ds
Vmemory
4.5V
6V
Mem_hl
Vmem_l
Vmem_h
Table 9: overview of the internal and external pixel array signals.
The Precharge and Sample signals are the most straightforward signals. The internal
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