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Original question:

LDC1101: Temperature compensation strategies

LDC1101: Temperature compensation approach

Michael9q
Intellectual 565 points
Part Number: LDC1101

Hello there,

I discussed temperature compensation in previous post (thank you very much by the way):

https://e2e.ti.com/support/sensors/f/1023/t/887982

As I am finalizing the design one simplification came to mind. 

For wire wound coil of litz wire: instead of using external sensor, there may be use one of the wire from litz strand to measure temperature. One contact of sensor coil is common for LDC (INA) and MCU. The other contact is single wire from litz strand connected to MCU.

Can this connection somehow effect LHR measurement? For example additional circuit connected through ground between MCU and LDC.

Maybe this picture will explain it more:

(blue is connection to MCU where blue coil is single wire of litz wire wound with other wires in same strand connected at the end to MCU)

The measurement uses constant voltage (3.3VDC) and it measures resistance of single wire.

Thank you for your answer,

Michael 

  • 0
    TI__Expert 7599 points

    Hi Michael,

    It's an interesting solution. 

    We have tested LDC with your approach and one downside with your approach is the the INA which has a connection to MCU can contribute to degradation as the INA pin is driving the coil to resonance. The impedance between the Coil and the MCU which is an uncontrolled parameter can cause concerns and needs to be tested. 

    As described in the post ? Have you considered using the temp sensor ? We do have thermistors in our portfolio. 

  • 0 in reply to Arjun_Prakash
    Intellectual 565 points

    Thanks for answer Arjun,

    yes, I was expecting it. Other solution is to use direct temperature sensor close to sensing coil. I was thinking of TMP112.

    Thanks,

    Michael