ADF4355-3

Sir,

I had designed recently ADF4355-3 own board.In that I want to know

   1. whether Vvco and Vdd of ADF4355-3 can be given same 3.3v from one regulator or not?

   2. what happens if these  Pin23(Vref) and Pin24(Vbias) are connected to 3.3v?

   3.Does any thing happens to the chip if the above pins are connected to supply?

   4.I am not able to see output due to this condition or not?

   5. Does output depends upon these pins(23,24)?

  • 0
    •  Analog Employees 
    on Dec 20, 2016 8:43 PM

    Hi ,

     whether Vvco and Vdd of ADF4355-3 can be given same 3.3v from one regulator or not? yes, but each pin should be separately decoupled

       2. what happens if these  Pin23(Vref) and Pin24(Vbias) are connected to 3.3v?  these pins should NOT be connected to 3.3Volts, see the datasheet page 33

       3.Does any thing happens to the chip if the above pins are connected to supply? depending on the current drawn , you may have permanently damaged the part

       4.I am not able to see output due to this condition or not? please connect as per figure 42, if you are still not getting an output, you should replace the part

       5. Does output depends upon these pins(23,24)? all pins need to be connected as per the datasheet recommendations in order to get the expected output.

  • Hi,

    We are using your evaluation board of synthesizer ADF4355-3.We are feeding externally 122.88MHz as reference,from a clean source without spurs.We locked 4355-3 and ensured 1KHz resolution.We are observing at every setting of output frequency the spurs at the offset of 80KHz either side @50dBc down.We need spur spec better than 60dBc.Can you please suggest how to reduce these spurs.Your immediate reply is appreciated.

  • Sir, 

    We are using your evaluation board of synthesizer ADF4355-3.We are feeding externally 122.88MHz as reference,from a clean source without spurs.We locked 4355-3 and ensured 1KHz resolution.We are observing at every setting of output frequency the spurs at the offset of 80KHz either side @50dBc down.We need spur spec better than 60dBc.Can you please suggest how to reduce these spurs.Your immediate reply is appreciated.

  • Sir,

    I am using AF4355-3 eval board with its on board 122.88 MHz oscillator.I had observed that in some frequencies like  ex:3440.640MHz no spurs are seen here. But when we shift that in 1KHz spurs are seen how to remove them please send us solution.