LUPA-4000_07 Datasheet, PDF (16/38 Pages) Cypress Semiconductor – 4M Pixel CMOS Image Sensor

LUPA-4000
Timing and read out of the image sensor
The timing of the LUPA-4000 sensor consists of 2 parts. The
first part is related with the control of the pixels, the integration
time and the signal level. The second part is related with the
readout of the image sensor. As this image sensor is able for
full synchronous shutter, integration time and readout can be
in parallel or sequential.
In the parallel mode the integration time of the frame I is
ongoing during readout of frame I-1. Figure 11 shows this
parallel timing structure
Figure 11. Integration and read out 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.
The LUPA-4000 sensor also can be used in sequential mode
(triggered snapshot mode) where readout and integration will
be sequentially. Figure 12 shows this sequential timing
sequence.
Figure 12. Integration and readout sequentially
Integration I
Read frame I
Integration I + 1
Read frame I + 1
Timing of the pixel array
The first part of the timing is related with the timing of the pixel
array. This implies the control of the integration time, the
synchronous shutter operation and the sampling of the pixel
information onto the memory element inside each pixel. The
signals needed for this control are described in the previous
paragraph 3.9 and in Figure 10.
Figure shows the external applied signals required to control
the pixel array. At the end of the integration time from frame
I+1, the signals Mem_hl, Precharge and Sample have to be
given. The reset signal controls the integration time, which is
defined as the time between the falling edge of reset and the
rising edge of sample.
Document Number: 38-05712 Rev. *B
Page 16 of 38