AD5342, question on reference input

Hi,

 

Please let me ask what is impedance value of reference input(VrefA and VrefB) of AD5342, when it is not powered ?

 

We are now studying one issue of our board, and it seems reference input is powered before the part is powered. To understand what is occured, we would like to know the value of impedance.  BUF pin is connected to +3.3V, but it should be 0V by connected to GND when it is not powered.

 

Thank you very much for your support,

 

Best Regards,

Parents
  • Hi Miguel,

    We found that BUF setting is affected to what is happened at the reference input. Datasheet describes BUF setting for two different mode of buffered and unbuffered and their impedance differences, however nothing described in case of unpowered.

    Could you please add the matter of BUF setting into my previous questions, how is BUF setting effect to reference input, in regard to impedance of power source at VDD, input frequency for Vref, when the device is not powered.

    Sorry to these complicating query but your helps would be always appreciated

    Best Regards,

Reply
  • Hi Miguel,

    We found that BUF setting is affected to what is happened at the reference input. Datasheet describes BUF setting for two different mode of buffered and unbuffered and their impedance differences, however nothing described in case of unpowered.

    Could you please add the matter of BUF setting into my previous questions, how is BUF setting effect to reference input, in regard to impedance of power source at VDD, input frequency for Vref, when the device is not powered.

    Sorry to these complicating query but your helps would be always appreciated

    Best Regards,

Children
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