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AD7761 imporve Synchronisation speed

Question asked by EngJunkie on Jul 20, 2018
Latest reply on Aug 13, 2018 by EngJunkie

Hey everyone,

 

I've got three AD7761's in a daisy chained configuration. I've followed the datasheet to the letter when designing the circuit and it works perfectly although the synchronization is slower than ideal.

 

Currently my routine after powering them up is the following:

 

I apply 2 reset pulse followed by 2 start pulses.

 

In between each transition from high to low or vice versa I have a 100 millisecond delay just as to not apply the pulses too fast.

 

After this I activate all the channels by making the standby pins low. At this point the output activates, but I can clearly see that its not synced yet. At this point it runs unsynced for quite a few samples and then syncs up and works perfectly.

 

Ideally I'd like to have the ADC's synced up when they start outputting data. Is there anything I can do to have them sync up properly before outputting data?

 

Thanks in advance for any help!

 

I know it is possible because I had old code that I can't seem to find anymore that initialized them in a way that when I activated the channels, they were completely in sync.

 

If any more info is required please let me know!

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