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AD9254S RBIAS

Question asked by sss on Sep 5, 2016
Latest reply on Sep 6, 2016 by David.Buchanan

Hi all,

 

In the datasheet at AD9254S RevB, there is only following description.

 "45pin, RBIAS, Analog output, External Bias Resister Connection."

How to select the resister value ?
Is it same value for the datasheet of AD9254 Rev0 ?


Our customer has start to evaluate the some samples of AD9254S.

Several samples have seen to degrade the SFDR, Spur.
Following is customer check points about the difference between OK and NG samples.
This is the measurement result in a state of mounting the 10Kohm resister.

 

1.SFDR/Spur NG samples.
 Power-down mode : RBIAS voltage 0.5V
 Operational mode : RBIAS voltage 1.0V

2.SFDR/Spur OK samples.
 Power-down mode : RBIAS voltage 0.0V
 Operational mode : RBIAS voltage 0.5V

 

Which is correct value of "RBIAS voltage" at each modes ?


Best regards,
sss

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