I have a custom board with AD9910, with it's differential output connected to a balun and single-ended output connected to output SMA connector. I have measured it's output using spectrum analyzer while in frequency sweep mode using DRG, from 100 MHz to 350 MHz. The output is noisy and not uniform compared to the output of the ADI's Evaluation board. I have measured the output at balun's differential side, single-ended end, and at IC's pin and there is no change in the output. I have verified the register configuration by plugging in the ADI Eval. board in same setup and firmware. Can someone experience with this DDS suggest what could have gone wrong with this chip.
AD9910 Custom Board Output (Freq. Sweep, 100 MHz to 350 MHz)
AD9910 Eval. Board Output (Freq. Sweep, 100 MHz to 350 MHz)
