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RTIA Value - Magnitude Issues

Question asked by kathyhanley on Sep 12, 2016
Latest reply on Sep 13, 2016 by kathyhanley

Hi there, 

 

I'm currently working on measuring the current through a sensor using the Amperometric Measurement Example. The example and setup works fine for measuring current values of microamps, however, we will be expecting current values between -2-10nA. We therefore need to increase the resolution from 4.88nA, and we have unsuccessfully been trying to do this by increasing the RTIA value.

It looks like the holder of the RTIA value is overriding as the resolution of the current repeats itself with multiples of RTIA of 7500 ( see attached graph).

We have changed the variables tmp and channel_gain in adi_AFE_TiaChanCal function to uint_64_t instead of uint32_t at the start of the afe_lib file, but this doesnt seem to work.

 

Any thoughts on the subject would be greatly appreciated, as the project is due soon so we really need to get this sorted.

 

Kind Regards,

Kathy

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