I am currently trying to use an AD9958/PCB board, however our output frequency seems to fail above a ~5MHz single tone. The signal before is half ok but the amplitude decreases as it approaches around the 5MHz frequency. Above it the signal just terrible and isn’t sensical. We’ve tried a variety of different reference clocks ranging from 50MHz to 500MHz both with and without multipliers but all produce the same result.
Another thing I’d like to ask is why the DAC filtered output (J7 and J8) only produced a signal but the unfiltered output (J3 and J4) output nothing.