AnsweredAssumed Answered

AD7608 SPI read out all zeros

Question asked by F.Zhang on Mar 18, 2015
Latest reply on Mar 20, 2015 by F.Zhang

Hi All,

 

I am trying to test the AD7608 device with a simple setup. I had my SPI signals correct on the pins.

The setup is as below:

OS0, RANGE, RESET = logic low

OS1, OS2, SER_SEL, /STBY, REF_SEL = logic high

decouple caps on supply and ref pins

 

But I did not get the data on DoutA.

tek0012.tif

1) /CS, 2) CONVSTA and CONVSTB 3) FRSTDATA pin 4)SCLK

tek0013.tif

1) /CS, 2) CONVSTA and CONVSTB 3) BUSY pin 4)SCLK

 

These two screen captures were took from the device, showing the SPI and CONVST signals were fine. But my readouts were all FFs the DO stayed high during the 18 bytes readout.

 

Any comments and help are greatly appreciated.

 

F.Z.

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