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PGA970: 4-wire LVDT support

Isee
Expert 5720 points
Part Number: PGA970

Hi Team,

Customer is using PGA970 for LVDT sensors. They are using TI software for 3-wire and 5-wire connection.

In that software a 4-wire AdcMode is defined but cannot be used further.

Can 4-wire be supported via software?

Regards

Andreas

  • 0
    TI__Guru** 113765 points

    Hi Andreas,

    Can you put the customer name and any project/opportunity information in the Notes section of the Thread Tracking Toolkit at the top of the thread? 

    Can the customer be a little more specific by what they mean by software?  Are they referring to the EVM software, example firmware, or TI Design firmware? I just don't know what the customer is referencing. Screen shots of what they see would also help.

    As to a 4-wire LVDT sensor, the sensor itself would only be connected to a single secondary (S1) ADC input.  In the end you would only get the ADC result from the differential input and no phase determination.

    Best regards,

    Bob B

  • 0 in reply to Bob Benjamin
    TI__Expert 5720 points

    For programming of the PGA970 we use Code Composer Studio with software which our former developer taked from TI and probably adapted for our hardware.

    The software consists of more files, I send you the source code in the attachement.

     

    We redesign now our measuring device with LVDT sensor. The device is software configurable for 3-wire or 5-wire connection. I would like to extend it for 4-wire connection in configuration 1 or configuration 2, as in the datassheet of PGA970 described. I would to get ADC result from the differential input with information about the direction from the midpoint

  • 0 in reply to Isee
    TI__Guru** 113765 points

    Hi Andreas,

    Can you please put the customer name and any project/opportunity information in the Notes section of the Thread Tracking Toolkit at the top of the thread?

    I removed the customer code from the previous post.  As to providing support, this appears to be an ask to develop the code for the customer.  This is not something TI would normally do, and that is why we provide the example code and resources for the customer to develop there own code (or find someone to do so).

    As to the process itself, they would need to properly configure the PGA970, and then only use one ADC for the measurement (depending on which ADC the 4-wire LVDT would be connected).  They would need to determine what the midpoint is and the direction based on values being returned.

    I do not have any LVDT or simulators available, so it would difficult for me to help in any way with the code.  I'm not sure what is meant by configuration 1 or configuration 2.  So I cannot comment further regarding what they desire.

    Best regards,

    Bob B