paphillips

Multiple AD7147 - Shield Sychronization

Discussion created by paphillips on Oct 7, 2016
Latest reply on Oct 21, 2016 by Maurice

There is a PDF (2009) referenced in this post describing how to synchronize two AD7147 shield excitation signals:

 

AD7147 

 

However, there are several other posts indicating it is not possible (can't tell the original post dates or chip revision level as these posts were archived in 2016):

 

AD7147: Multiple devices in one application 

AD7147: Can several AD7147 be used in parallel to realize a remote control with 35 buttons?  

 

Questions:

 

  1. Has anyone successfully used this sychronization technique in a design?
  2. Will the undocumented TEST CONTROL bit 4 in register 0x44 referred to in the PDF work on AD7147 chip rev E?
  3. This technique indicates an external clock is applied to the GPIO pin to synchronize the device shields. Is this clock to be at the ACShield frequency of 250kHz, or some other rate?

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