AD9822 output code

Hi,

I am working on the AD9822 CCD signal processor in bench and verifying its functionality in 1-channel CDS mode.

My input signal is CCD waveform with reference level at 2V and data level at 1V at 1MHz frequency.

I have programmed the offset voltage as 3V in the configuration register.

The clocks (ADCCLK,CDSCLK1 & CDSCLK2) are also operated in 1MHz frequency.Timing and levels are checked and followed as per the datasheet spec.

I am observing the output code to have random drop to 0V.(Image shown below)

The plot is number of samples vs the output code (in terms of voltage)

When 6000 samples are captured, around 900 samples drops to 0V randomly.

The hardware setup is as per the application diagram of datasheet.

Please help me to sort out the issue.

Thanks

Pavithra Joshi