This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

About the problem of LDC1051 setup

Guru 19475 points
Other Parts Discussed in Thread: LDC1051

LDC1051 is evaluated.

Although it operates normally at 25℃, it becomes oscillator overloaded and stops at 45℃.

  (Register table 13)

If a mistake occurs about a setup of LDC1051, please let me know.

・A setting register is attached.

The place changed from the default is painted yellow.

3465.LDC1051_140908_1.xlsx

 ・Coil is 52μH and 82pF.

Best regards,

Satoshi

  • Hello Satoshi,

    what do you mean with 'overloaded'?

    Is the sensor still oscillating (please check with a scope)?

    Or are you reaching the maximum RP code?

  • Dear Ben Kasemsadeh-san

    Thank you for reply.

    "Overload" mean that OSC states become "1" (Resister address:0x20,Bit-7).

    And, oscillating is stopped.

    Rp was not reach Rp_Max.

    The result of scope is check to a customer, I will report again after understanding.

     

    Best regards,

    Satoshi

     

  • Hello Satoshi,

    Rp of the sensor must be between Rpmin and Rpmax that are set in the register settings. If Rp is lower than the Rpmin setting, the sensor will stop oscillating and the overload flag will be asserted. Increasing temperature lowers Rp of the sensor.

    I assume that your sensor resistance at resonance drops below the Rpmin setting as you heat up your sensor. Try reducing the Rpmin setting. If you already use an Rpmin setting of 798 Ohm (minimum for LDC1051), you need to increase sensor impedance by changing either your sensor capacitor and/or your sensor inductor.