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TMAG5273: TMAG5273

Tom Maricic
Prodigy 20 points
Part Number: TMAG5273
Other Parts Discussed in Thread: TMAG5170

hi,

I may be interested in your TMAG5273 3d hall-effect sensor for an upcoming project where we are required to measure heading (N,S,W,E) in an underground sensor, but I would like firstly to establish the suitability of this part please (or another TI part if you so recommend).  

What is the accuracy of this part (as a percentage), and what if anything is required in terms of calibration/configuration to obtain/guarantee this accuracy figure ?
Do TI provide software relating to this part ?
Can the part be used in any orientation or must X,Y be in the horizontal ?  We would prefer to have X,Z in the horizontal simply because our PCB will be orientated vertically.
In our application the part will not always be perfectly flat, so how do we compensate for this and still obtain the specified accuracy ?
Is stock available now and if so from where ?  Likewise for any dev kit associated for this part ?

Thank-you.

PS.  I was kindly advised by your colleague from Customer Support, Jonard Rico, to post to this forum.

  • 0
    TI__Expert 7505 points

    Hi Tom,

    The accuracy that you will see would depend on the entire system, which includes the magnet, the distance from the magnet to the sensor, mechanical tolerances, and other factors.  The following tool that may be used to determine the field that will be observed by our devices based on your system's parameters:

    https://www.ti.com/lit/zip/slyr071

    Section 8.1.5 of the TMAG5273 datasheet provides an equation to estimate the TMAG5273 error you will see based on the applied field.  This does not include any additional error sources you will see from outside the device, which includes mechanical and magnetic tolerance errors.  The amount of calibration needed would depend on what accuracy you are trying to obtain.  Depending on the accuracy needed, you may need to do offset and sensitivity gain correction.  In addition, for high precision devices, I would recommend the TMAG5170, which is our most precise 3D sensor.

    Our part can be used in any orientation.  It is just that the mapping of the magnetic field to the device's x, y, and z measurements would vary.

    You can order the TMAG5273 from the following page:

    https://www.ti.com/product/TMAG5273 

    Here is also a link to the dev kit:

    https://www.ti.com/tool/TMAG5273EVM 

    Regards,

    Mekre

  • 0 in reply to Mekre Mesganaw
    Prodigy 20 points


    hi Mekre,

    thank-you very much for your quick response.

    Apologies up front for my lack of knowledge in this subject hence the questions. In our application we need to measure heading, for example 4.5degrees west of north, noting that the measuring device may not be with its two horizontal planes perfectly horizontal. There are no external magnets, as mentioned in the datasheet, except of course for the Earth's magnetic field. Is this part suitable for our application ? Section 8.2.3 discusses an "Angle Measurement" example, but then introduces external magnets so I'm not sure if the device can be used as we'd like.

    If it is suitable for our application then can it provide these angles accurate to within about one or two degrees assuming its optimal settings ? If not then what is the best it can do in such applications again assuming optimal settings ? Ideally, we would not need to do any special calibration in Production hence it would be nice to know the 'as is' accuracy of the device ?

    I assumed there'd be three values output by the TMAG5273, for X, Y and Z, which we then plug into an equation to obtain this heading. There are various links to spreadsheets, equations, etc, but I'm struggling to clearly see what that equation is. Maybe it's not quite as simple as I had imagined - can you point me in the right direction ? And the other question related to tilt - can it provide this heading even if the two horizontal axes are not perfectly horizontal ?

    I also assumed there'd be an accuracy figure specified. I see numbers such as +/-1.0 degrees specified for the "Y-Z Angle error in full 360 degrees rotation" - is this the answer, or only part of the answer ? You mentioned equation 8.1.5, but in section 8.1.6 it mentions Error Calculation During Angular Measurement - is that more relevant seeing as we're interested in the heading ? This takes me to a 2D Angle Error Calculator which mentions "This tool does not account for conditions such as tilt ...", and in any case I don't see an equation which we could use ?

    Thanks also for you recommendation of the TMAG5170. I didn't think we could consider this part due to lack of availability in digikey and mouser. Is it basically the same thing, but just more accurate ? For the "Y-Z Angle error in full 360 degrees rotation" this part is +/-0.5 degrees compared to the previous 1.0 degrees - are these numbers 'as is' or do they only apply after calibration ?

    Actually the TMAG5170 datasheet includes an additional table, Table 8-2, showing Angle error for 360o rotation at 25oC of 1.5 degrees. Is this the 'as is' accuracy without any additional calibrating ? This is all based on a magnetic field range of 100mT, peak X,Y field of 80mT, and CONV_AVG=101b - do you know are these field values applicable in our application (heading measurement based on Earth's magnetic field) ?

    Is there any associated software provided by TI for this/these parts ?

    kind regards,

    Tom

  • 0 in reply to Tom Maricic
    TI__Expert 7505 points

    Hi Tom,

    Our device is better suited for detecting the magnetic field from a nearby magnet.  It is not meant to measure the Earth's magnetic field, which is relatively small in magnitude compared to the ideal sensing range of the TMAG5170 or TMAG5273.

    Regards,

    Mekre