LUPA-4000 Datasheet, PDF (24/49 Pages) Cypress Semiconductor – 4M Pixel CMOS Image Sensor

LUPA-4000
Data Sheet
The rise and fall times of the internal generated signals are not very fast (200nsec). In
fact they are made rather slow to limit the maximum current through the power supply
lines (Vmem_h, Vmem_l, Vres, Vres_ds, Vdd). Current limitation of those power
supplies is not required. Nevertheless, it is advisable to limit the currents not higher
than 400mA.
The power supply Vmem_l must be able to sink this current because it must be able to
discharge the internal capacitance from the level Vmem_h to the level Vmem_l. The
external control signals should be capable of driving input capacitance of about 10pF.
3.10.1 Digital signals
The digital signals control the readout of the image sensor. These signals are:
• Sync_y (AH): Starts the readout of the frame. This pulse synchronises the y-
address register: active high. This signal is at the same time the end of the
frame or window and determines the window width.
• Clock_y (AH): Clock of the y-register. On the rising edge of this clock, the
next line is selected.
• Sync_x (AH): Starts the readout of the selected line at the address defined by
the x-address register. This pulse synchronises the x-address register: active
high. This signal is at the same time the end of the line and determines the
window length.
• Clock_x (AH): Determines the pixel rate. A clock of 33MHz is required to
achieve a pixel rate of 66MHz.
• Spi_data (AH): the data for the SPI
• Spi_clock (AH): clock of the serial parallel interface. This clock downloads
the data into the SPI register.
• Spi_load (AH): when the SPI register is uploaded, then the data will be
internally available on the rising edge of SPI_load
• Sh_kol (AL): control signal of the column readout. Is used in sample & hold
mode and in binning mode
• Norowsel (AH): Control signal of the column readout. (See timing)
• Pre_col (AL): Control signal of the column readout to reduce row blanking
time
• Voltage averaging (AH): Signal required obtaining voltage averaging of 2
pixels.
3.10.2 Test signals
The test structures implemented in this image sensor are:
• Array of pixels (6*12) which outputs are tied together: used for spectral
response measurement.
• Temperature diode (2): Apply a forward current of 10-100µA and measure the
voltage V_T of the diode. V_T varies linear with the temperature (V_T decreases
with approximately 1,6 mV/°C).
• End of scan pulses (do not use to trigger other signals):
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Contact: [e-mail] Document #: 38-05712 Rev.**(Revision 1.2 )
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