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Question asked by keddy on Apr 10, 2017
Latest reply on Apr 19, 2017 by keddy

Hi there,


My customer is using AD9850 to generate ultrasonic sinewave of 137KHz with an 100MHz reference clock in. In most cases, it works well. However, sometimes it fails to output sine wave. Instead, it outputs non-regular waveforms. When it fails, the Data bus bit[2] goes to uncertain value-neither logic low nor logic high. I wonder what cause this problem? 


In the datasheet, there is no detail explanation on D[0:1] for the Control (page 10 of Rev H) and D[2] for Power-down in W0 word in Table III. Can help to advise? 


when customer re-write the control commands, DDS still can not recover to sine wave. The only way to make it recover, either reset DDS pin 22 or power-down the board. Is there any way to diagnose and recover?



Keddy Yang