• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 31 subscribers
  • Views 208 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TMAG5273: Differential Linearity vs. Sensitivity Linearity Error

MMDuctance
Prodigy 160 points
Part Number: TMAG5273

Hello everyone

I am working on an application in which I want to use TMAG5273 sensor. In this application, I need to sense harmonic magnetic field ripples (amplitudes are around 200uTpeak, sinusoidal at 100Hz) in the presence of a constant background magnetic field (ranging from -20mT to 20mT).

I am basically wondering how much the measurement of the small, sinusoidal magnetic field ripple amplitude will change as a function of applied background magnetic field.

The datasheet mentions the "sensitivity linearity error" for the A1 characteristic as 0.1%. So does this mean, that if I slowly change the constant background magnetic field from -20mT to 20mT, the measurement of the AC magnetic field amplitude should only change by approx. 0.1%?

  • +1
    TI__Genius 15290 points

    MMDuctance,

    Thank you for reaching out with your question on E2E.  Sensitivity linearity error can be thought of similarly to the gain linearity error of an op-amp or an ADC.  That is, this describes the maximum deviation from the ideal straight line between maximum and minimum output values.  Ideally, the response is perfectly linear, but when measured on an actual device there is some deviation from this ideal line.  An example can be seen in the video at the following link at 13:33.

    https://training.ti.com/specifications-3d-hall-effect-sensors

    TMAG5273 will detect the absolute field that results from the combination of the existing fields.  The field with 200 uT peak will interact somewhat with the larger background field which ranges from +/- 20 mT.  The resulting field is then integrated by using the Hall-effect element and then converted to a digital output by the sensor.  The primary challenge I expect you will encounter is that the input referred noise of this sensor is typically about 125 uT.  To improve this, it is possible to enable averaging which will reduce the effective noise, but will increase the total time required for conversions.  Since the input signal is 100 Hz, it may still work well to apply some averaging to reduce this effect.

    Thanks,

    Scott