AD9959 stops random

Question

Dear All, 
 I'm playing with an AD9959, need 3 phase generator with accurate freq and phase shift between the outputs. Using single tone. My problem is, after I initialize, it works for a wile, than, sometime after a few minutes, other time after half hour it stops and the output signals are stuck at lowest on all channel (not zero, negative max after amplification). 
 I'm trying to find the cause for several hours now, but no success. The power seems to be clean and stable, no foreign signals on control lines or reset pin. 
 What could cause the chip stuck at negative maximum? 
 If I put it in reset, it is at zero level at the output, not negative max. 
 Thanks! 
 JG

Giordano21 · Accepted Answer

Hi Jules! 
 Thank You for looking into these. 
 I've designed and built my own board and use an stm32 controller to control it. 
 BUT, now I've inserted pullup resistors to chip select, pull down on IO update and DDS_reset and able to separate the control board from the DDS board after setup. After I separate, it runs forever. This means it is not DDS related. 
 I was also playing with the input signals manually and realized if I insert a DDS reset than I get this output. This means I insert a DDS reset and (this is not relevant here, but) at sending the uC to sleep I have a transient on the reset signal. If I do not send to sleep, it does not happen. 
 On the other hand, unfortunately it has no connection to my other issue with the phase reset during frequency update. 
 Thanks, 
 JG)

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AD9959 stops random