.txt basic IQ Datafiles

Hi there,

I'm working with the zcu102/adrv9009  and trying to understand the binary .txt format here https://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/software/basic_iq_datafiles

My sample rate is 245.76 MSPS and have used the binary .txt to create sinewave on the I/Q channels 90 deg offset- scaled to 30000. I get the waveforms I expect- basically tones at some frequency scaled to amplitude 30000.  An example of the beginning of one of my .txt is:


30000.0 0.0

29025.0 7587.0

26163.0 14680.0


But then when I create a text file similar to 10.txt or 11.txt, I start seeing square waves with amplitude ~15000 on the I/Q channels.  Can someone explain why this occurs? 

I would have expected instead to see an ADC code of 1 (with some noise) at channel Q and an ADC code of 0 (with some noise) on channel I.  And I'd expect these values to be constant in time not varying like a square wave.



1 0

1 0

1 0


Thanks for your help!



changed amplitude scaled value to 30000
[edited by: mmedrano at 6:26 PM (GMT 0) on 31 Jul 2020]