Hi,
I'm interfacing the ADS8881 with Altera DE1 FPGA board. The sampling rate is around 200ksps.
The ADC output has weird behaviors. When sampling a DC input, the ADC output is correct for some samples and then becomes another different value for some samples. And then repeats such behaviors. The plot below is one example. I converted the output codes to differential voltage. I gave a 0V DC input (differential) to the ADC. The first 250 samples, the output is around 0. But from 250 to 500 samples, the output shows around 0.6V. And it repeats like 500 samples of 0V and 250 samples of 0.6V.
Not sure if the ADC internal circuit resetting or oscillating to a different value?
I checked the voltage at the input node of the ADC is always 0 V. Does anyone experience similar issues? Please help!
