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Original question:

TSW1400EVM: Pattern File request

DAC3482EVM: RF OUT dissonance

Jong-min Kim
Prodigy 70 points

Part Number: DAC3482EVM
Other Parts Discussed in Thread: DAC3482

Hi

By using the DAC3482 part, you can get the desired output.

However, when the span is large, there is no problem, but when the span is small, there is a lot of dissonance.

So, I checked the output of TSW1400 EVM and EVM3482 EVM, and there is a lot of dissonance here too.

Below is the example of setting both Video BW/Res BW to Auto in EVM and checking the CW signal with 1MHz/100MHz Span.

I wonder if this result is correct.

Regard

  • 0
    TI__Guru* 91947 points

    Jong-min,

    This does not look correct. Run the DAC in NCO only mode and see how the zoomed in view looks. This will isolate the issue between the DAC and TSW1400. Are you seeing any alarms? Have you tried running the IO_test? This could be a timing issue. How does the output look when using a slower DACCLK?

    Connect the output to an oscilloscope. This can help with showing possible issues.   

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 70 points

    Jim

    -> Same with using NCO.

    -> There is no alarm.

    -> I haven't tried IO_test.

    -> I haven't tried applying the slower DACCLK. It's not as simple as you have to change the whole scheme.

    Can you check the output waveform below that you sent me before with 1MHz span?

    Regards

  • 0 in reply to Jong-min Kim
    TI__Guru* 91947 points

    Jong-min,

    If you are seeing this with just the NCO enabled, I would suspect the spectrum analyzer or your clock source are having problems. I would suggest sending the clock source directly to the spectrum analyzer and see what you get.

    Regards,

    Jim