AnsweredAssumed Answered

AD7172-4 Even Numbered Channels

Question asked by caveerappanW on Jan 19, 2017
Latest reply on Jan 22, 2017 by JellenieR

Hi All

 

After finally getting the above device to behave sensibly, I have come across another issue. While it does not completely stop me using the chip, I would like to get to the bottom of the issue.

 

From what I am aware, this device allows any of the 9 physical input pins to be directed to any of the 8 internal measurement channels. These channels then can be directed to any one of 8 'setups'. Each setup then has associated, filter, gain and offset settings. 

 

I have setup all eight channels for internal chip testing, (i.e. Vdd and Vss as the reference and the 'test pair' which produces 1V as inputs), thereby not relying on any external input. 

 

I have all the 8 'setups' identically as have the filters. The gain and the offset have not been altered. 

 

Now when the channels are directed to setups 1, 3, 5, 7 - the measurement I get is around the 1 V mark. 

 

However when directed to setups 0, 2, 4, 6 - the measurement value is 0xFFFFFF.

 

Now given the setup, filter, gain and offset are configured identically, I am not sure why the device is behaving like this. 

 

While I only really require 2 setups in my application, it would be nice to get to the bottom of this problem.

 

Anyone have any ideas.

 

Thank you

 

Kind regards

 

Chithambaram 

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