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Problem with output of AD9649 Evaluation Board

Question asked by kinyau94 on Jul 15, 2016
Latest reply on Jul 19, 2016 by DougI

I have a AD9649 Evaluation Board and I have read through the user guide EVALUATING THE AD9266/AD9649/AD9629/AD9609 ANALOG-TO-DIGITAL CONVERTERS [Analog Devices Wiki] , I am trying to get the ADC 2 complement output by standalone mode (without the SPI communication).

I have set the Jumper as shown below:

J203: Pin 1 to Pin 2 (MODE_OR to LED)

J302: Pin 8 No Jumper  (Standalone mode)

          Pin 2 No Jumper (Default Mode)

          Pin 5 to Pin 6 (2's Complement)

J605: Pin 1 to pin 2 ( internal oscillator)

J201 : Pin 2 to Pin 3 (internal 1V reference)

J202: No jumper.

I have tested by input 1V to the input_A, I should expecting "01 1111 1111 1111", but what I get is fluctuating random numbers range from negatives to positive (majorly negative numbers).

Can anyone give some guide on how to setup  standalone mode for  AD9649 Evaluation board?

Thank you!