LUPA-4000_07 Datasheet, PDF (19/38 Pages) Cypress Semiconductor – 4M Pixel CMOS Image Sensor

Figure 15. X- and Y-addressing
LUPA-4000
Table 13. Read-out timing specifications
Symbol
a
b
c
d
e
f
Name
Sync_Y
Sync_Y-Clock_Y
Clock_Y-Sync_Y
NoRowSel
Pre_col
Sh_col
g
Voltage averaging
h
Sync_X-Clock_X
Value
>20 ns
>0 ns
>0 ns
>50 ns
>50 ns
200 ns (more information on this timing
can be found in section 4.2.2.a)
>20 ns
>0 ns
As soon as a new line is selected, it has to be read out by the
output amplifiers. Before the pixels of the selected line can be
multiplexed onto the output amplifiers, one has to wait a
certain time, indicated as the ROT or Row overhead time
shown in Figure 15. This is the time to get the data stable from
the pixels to the output bus before the output stages. This ROT
is in fact lost time and rather critical in a high-speed sensor.
Different timings to reduce this ROT are explained in next
paragraph.
During the selection of 1 line, 2048 pixels are selected. These
2048 pixels have to be readout by 1 (or 2) output amplifier.
Please note that the pixel rate is the double frequency of the
Clock_x frequency. To obtain a pixel rate of 66 MHz, one needs
to apply a pixel clock Clock_x of 33MHz. When only 1 analog
output is used 2 pixels are output every Clock_x period. When
Clock_x is high, the first pixel is selected, when Clock_x is low,
the next pixel is selected. Consequently, during 1 complete
period of Clock_x 2 pixels are readout by the output amplifier.
If 2 analog outputs are used each Clock-X period 1 pixel is
presented at each output.
Document Number: 38-05712 Rev. *B
Page 19 of 38