AD9822: O/P data in 3 channel mode

Document created by analog-archivist Employee on Feb 23, 2016
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I have a problem with an ADC. I use the AD9822 analog / digital converter with
the TCD2558D CCD sensor. This CCD sensor is 5340 dots by 3 colours.

I use the ADC in 3 channels CDS mode. This ADC is programmed to switch data in
the order "red, green, blue".
I understand that the ADC outputs data byte by byte (for a same colour, high
byte first then low byte, then next colour …).


Refer to the MUX register description on page 13 of the datasheet. Where we
state the following:

MUX Register
The MUX register controls the sampling channel order in the AD9822. Bits D8,
D3, D2, D1, and D0 should always be set low. Bit D7 is used when operating in
3-channel mode. Setting Bit D7 high sequences the MUX to sample the red channel
first, then the green channel, and then the blue channel. When in this mode,
the CDSCLK2 pulse always resets the MUX to sample the red channel first (see
Figure 3). When Bit D7 is set low, the channel order is reversed to blue first,
green second, and red third. The CDSCLK2 pulse always resets the MUX to sample
the blue channel first.