Have three unlearned questions about AD9851

Application here is to provide a signal of between 57 and 62 MHz at -5 to +12 dBm level (with ability to set) ( in 50 ohm system).

I'm considering what kind of topology to use.  I like  idea presented in Figure 9 and 10 of the AD9851 data sheet.  It is easy for

me to add a DAC for some amplitude control.

I am so much of a beginner at this.  I very much appreciate anyones advice or help, and any comment will be welcomed.  Even if I have totally

incorrect approach I will be thankful to know.

1)  What signal levels can I expect to be at the transformer output?

2)  How much change will be available by using DAC like figure 10?

3)  Plan is to put anti-alias filter at output of the transformer.  Is this good choice, or is another better?

Thanks so very much for your kind attention.

  • 0
    •  Analog Employees 
    on Jun 9, 2013 8:03 PM over 7 years ago

    Hi tfkeel,

    1.) The signal output level depends on your current and load values. But the level should not go beyond the voltage compliance range which is specified in the datasheet (1.5 V and -0.5 V).

    2.)The change of current will be dependent on the resolution of the DAC. Using a 10 bit DAC would introduce 2^10 quantizations for your current output.

    3.) If you're only interested in the frequency output below nyquist for single tone applications, then having an anti-alias filter is really necessary at the output of the transformer.



  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:52 PM over 2 years ago
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin