LDC5072-Q1: Sensor design tool target dimensions & inner margin

Part Number: LDC5072-Q1

Tool/software:

Hi all,

is it possible to scale the inner radius of the coils and the target individually? The tool seems to scale the inner radius of the target and the coil set equally when the parameter "inner margin" is changed. Hence, it is impossible to realise an offset between the target inner radius and coil inner radius. 

Thank you!

Philipp

  • Phillip,

    Have you tried using the Custom Sensor tab in the tool?

    Regards,
    John

  • Hi John,

    thanks for your answer. I have tried the custom sensor tab. However, this only creates custom gerber files and spice models. I would like to simulate the design before creating the gerber files to calculate the error of the angle. However, clicking the button "design sensor" uses the parameters from the first tab and not the custom sensor tab. I can never get the error below 4° which is why i would like to change this setting in the first place.

    Best,

    Philipp

  • Thanks for the feedback Philipp.

    I will look at this some more and update this thread before the end of the week.

    Regards,
    John

  • Philipp,

    Apologies, but I was unable to look at this die to multiple conflicts.

    I will begin looking at it today and will provide a daily update until your issue is closed.

    regards,
    John

  • Philipp,

    Just to confirm: Even when using the Custom Sensor tab, the tool is taking the input parameters from the Mechanical Design tab?

    Do any messages appear in the Custom Sensor Log messages that indicate this?

    Do the log messages mention difficulty in creating a solution with the given parameters? 

    Regards,
    John

  • Hi John, 

    thank you very much for continuing to offer your help on this problem. The procedure is as follows: 

    1. The mechanical parameters are edited and the button "Design Sensor" is pressed. The optimisation simulation runs (at this point, no matter what the mechanical parameters are, the angle error is always above 4° which I reckon is quite high)...

    2. In the custom sensor tab, the parameters are changed (my assumption is that changing the sense coil diameters might influence the angle error) and the button "Use this custom design for..." is clicked. When creating Gerber files at this point, the changed parameters are output in the gerber files correctly.

    3. The button "Design Sensor" is clicked once again. Now all the parameters are reset and the Custom Sensor parameters ignored. Hence the assumption that the custom sensor tab doesn't actually influence the sensor's design. Is this correct? It would be nice to see this implemented in the tool.

    This is the log that appears when performing the steps described above:

    Sensor Maximum Raw Error Estimate=4.1deg
    Overall coupling is 1:91.3 and required gain is 11.0 V/V
    Target Pedal is 0.119 ohms
    Q-Sense is 0.728 ohms
    I-Sense is 0.738 ohms
    Excitation is 3.637 ohms
    Resistance:
    Target Pedal is 641.62 nH
    Q-Sense is 0.12 uH, CW is 0.07 uH, CCW is 0.07 uH, Coupling is 0.17
    I-Sense is 0.14 uH, CW is 0.07 uH, CCW is 0.10 uH, Coupling is 0.15
    Excitation is 4.76 uH
    Self Inductance:
    Q-Sense CCW is 148.08 + 0.00 x sin(0.00 x THETA + 0.00) nH
    Q-Sense CW  is -148.30 + 0.00 x sin(0.00 x THETA + 0.00) nH
    Q-Sense     is -0.21 + -0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense CCW is 148.30 + 0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense CW  is -147.53 + 0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense     is 0.77 + -0.00 x sin(0.00 x THETA + 0.00) nH
    Mutual Inductance: Excitation to Sensor
    Target CCW Pedal is 6.72 + 5.10 x sin(4.00 x THETA + -79.36) nH
    Target CW  Pedal is -6.88 + 5.06 x sin(4.00 x THETA + -80.42) nH
    Target     Pedal is -0.16 + 10.16 x sin(4.00 x THETA + -79.89) nH
    Mutual Inductance: Target to Sensor-Q
    Target CCW Pedal is 6.65 + 5.20 x sin(4.00 x THETA + 14.48) nH
    Target CW  Pedal is -6.82 + 5.19 x sin(4.00 x THETA + 9.35) nH
    Target     Pedal is -0.18 + 10.38 x sin(4.00 x THETA + 11.92) nH
    Mutual Inductance: Target to Sensor-I
    Target Pedal is 191.53 + 0.42 x sin(4.00 x THETA + 88.70) nH
    Mutual Inductance: Excitation to Target
     
    Channel Gain:  91.28V/V KXT: 0.110 KSIT: 0.069 KSQT: 0.073
    Building models for corners: 3 to 3.
    ...completed design process.
    E/M=4 Layers=3 Turns=3.
    ...completed capacitance calculations...
    | 153.65pF  -1.55pF -38.07pF |
    |  -1.43pF  34.59pF -14.70pF |
    | -79.18pF -52.95pF 530.46pF |
    ...determining charges/voltages...
    ...determining charges/voltages...
    ...determining charges/voltages...
    ...creating capacitance mesh...
    ...calculating the coefficients of capacitance...
    Mutual inductance SQ/T L=0.010130uH
    Mutual inductance SI/T L=0.000200uH
    Mutual inductance X/T L=0.191841uH
    Mutual inductance X/SQ L=0.000240uH
    Mutual inductance X/SI L=-0.000156uH
    Target inductance LT=0.643uH
    Target resistance RT=0.118 ohms
    Sense coil coupling=-0.1656 -0.0130
    Sense coil mutual inductance L=-0.0125uH
    Excitation coil resistance RX=3.648 ohms
    ...analyze sensor coil parameters...
    Excitation Coil: E/M:4 Layers=3 Turns=3 Spacing=0.450mm L=4.78uH
    ...sensor coils complete...
    Working please wait...
    Individual sense coil L=0.0757uH
    Total sense coil L=0.1495uH
    Total bifilar sense coil resistance RS=0.676 ohms
    Total bifilar sense coil inductance LS=0.1495uH
    Saliency Width=5.475mm L=0.15uH
    ...starting with the saliency width...
    ...optimizing the sense coil...
    Shape=0 Layers=3 Turns=3 Spacing=0.450mm L=5.02uH
    ...starting with the number of turns...
    ...optimizing excitation coil...
    Starting design process...
    GUI Version: 0.2.
    Now using custom design for saving and Gerber generation.
    Importing optimizer design.  Feel free to modify.
    Sensor Maximum Raw Error Estimate=4.1deg
    Overall coupling is 1:91.3 and required gain is 11.0 V/V
    Target Pedal is 0.119 ohms
    Q-Sense is 0.728 ohms
    I-Sense is 0.738 ohms
    Excitation is 3.637 ohms
    Resistance:
    Target Pedal is 641.62 nH
    Q-Sense is 0.12 uH, CW is 0.07 uH, CCW is 0.07 uH, Coupling is 0.17
    I-Sense is 0.14 uH, CW is 0.07 uH, CCW is 0.10 uH, Coupling is 0.15
    Excitation is 4.76 uH
    Self Inductance:
    Q-Sense CCW is 148.08 + 0.00 x sin(0.00 x THETA + 0.00) nH
    Q-Sense CW  is -148.30 + 0.00 x sin(0.00 x THETA + 0.00) nH
    Q-Sense     is -0.21 + -0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense CCW is 148.30 + 0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense CW  is -147.53 + 0.00 x sin(0.00 x THETA + 0.00) nH
    I-Sense     is 0.77 + -0.00 x sin(0.00 x THETA + 0.00) nH
    Mutual Inductance: Excitation to Sensor
    Target CCW Pedal is 6.72 + 5.10 x sin(4.00 x THETA + -79.36) nH
    Target CW  Pedal is -6.88 + 5.06 x sin(4.00 x THETA + -80.42) nH
    Target     Pedal is -0.16 + 10.16 x sin(4.00 x THETA + -79.89) nH
    Mutual Inductance: Target to Sensor-Q
    Target CCW Pedal is 6.65 + 5.20 x sin(4.00 x THETA + 14.48) nH
    Target CW  Pedal is -6.82 + 5.19 x sin(4.00 x THETA + 9.35) nH
    Target     Pedal is -0.18 + 10.38 x sin(4.00 x THETA + 11.92) nH
    Mutual Inductance: Target to Sensor-I
    Target Pedal is 191.53 + 0.42 x sin(4.00 x THETA + 88.70) nH
    Mutual Inductance: Excitation to Target
     
    Channel Gain:  91.28V/V KXT: 0.110 KSIT: 0.069 KSQT: 0.073
    Building models for corners: 3 to 3.
    ...completed design process.
    E/M=4 Layers=3 Turns=3.
    ...completed capacitance calculations...
    | 153.65pF  -1.55pF -38.07pF |
    |  -1.43pF  34.59pF -14.70pF |
    | -79.18pF -52.95pF 530.46pF |
    ...determining charges/voltages...
    ...determining charges/voltages...
    ...determining charges/voltages...
    ...creating capacitance mesh...
    ...calculating the coefficients of capacitance...
    Mutual inductance SQ/T L=0.010130uH
    Mutual inductance SI/T L=0.000200uH
    Mutual inductance X/T L=0.191841uH
    Mutual inductance X/SQ L=0.000240uH
    Mutual inductance X/SI L=-0.000156uH
    Target inductance LT=0.643uH
    Target resistance RT=0.118 ohms
    Sense coil coupling=-0.1656 -0.0130
    Sense coil mutual inductance L=-0.0125uH
    Excitation coil resistance RX=3.648 ohms
    ...analyze sensor coil parameters...
    Excitation Coil: E/M:4 Layers=3 Turns=3 Spacing=0.450mm L=4.78uH
    ...sensor coils complete...
    Working please wait...
    Individual sense coil L=0.0757uH
    Total sense coil L=0.1495uH
    Total bifilar sense coil resistance RS=0.676 ohms
    Total bifilar sense coil inductance LS=0.1495uH
    Saliency Width=5.475mm L=0.15uH
    ...starting with the saliency width...
    ...optimizing the sense coil...
    Shape=0 Layers=3 Turns=3 Spacing=0.450mm L=5.02uH
    ...starting with the number of turns...
    ...optimizing excitation coil...
    Starting design process...
    GUI Version: 0.2.
  • Phillip,

    I was able to create a custom design using the Custom Sensor tab.
    The starting point was to create a design from the Mechanical Design tab, and then save the design.
    The next step was to transition to the Custom Sensor tab and modify the input parameters to the desired values, and check the box "Use this custom design for "Use this custom design for "Save Design"..." before clicking the Create Gerber Files button.

    At this point, the tool won't create a Spice model for the custom design.
    That can only be done for a design done from the Mechanical Design tab.

    The Angle Error is only an estimate. A better way to estimate the angle error is to generate a Spice model and use it to run sims in Pspice.

    regards,
    John

  • Hi John, thank you. That clarifies a lot. I wish it were possible to create simulation parameters for a spice model from the custom design tab as well. But i might just order the PCB and check the performance on the hardware. Thanks a lot for your time!