Smartphone output impedance measurements

Discussion in 'Source Measurements' started by fraggler, Oct 10, 2017.

  1. fraggler

    fraggler A Happy & Busy Life

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    Normally, my google-fu is at least average, but I have struck out so far. Does anyone know of a resource that has smartphone output impedance measurements somewhat collated? I am specifically looking for my own phone, the Samsung Note 8 (Snapdragon version), but no luck at the moment.

    As a secondary question, how would one go about measuring the output impedance?
     
  2. kapanak

    kapanak Canucklehead - Friend

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    Silly, potentially obvious answer to the second question first: A resistor and a digital multimeter?

    I am not sure what the standards are for measuring output impedance of audio devices (low-tier google-fu), but you'd need a fixed frequency.

    I do not believe there is a cumulated place for all the phone output impedances data.
     
  3. Lyander

    Lyander Too sensitive for SBAF

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    I've actually been looking for such a database for a while now too, back when I considered saving up for Andros (eh, passed cuz I'm not much of an IEM guy anyway). The problem is that there are so many flipping (and non-flipping) phones released on tight cycles every year that aiming to measure them all, or even just the most popular models going from sub-$100 to iPhone-pricing is going to be a hell of a task. I guess you could stick to flagships, but that cuts out a lot of popular models as well.

    Huh, what if some people on here just set a standard for measurements (using not too expensive tools) so we could build a database of our own? Might be fun, really. Sure, it'd be MUCH easier if GSMArena just added the damn specs to their phone pages moving forward, but that's highly unlikely.
     
  4. Armaegis

    Armaegis Friend

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    Don't most smartphones have an opamp based headamp? or even integrated with the dac chip itself? With the exception of any with resistor pads for stability (doubtful) or short circuit protection (more likely?), I imagine it's a non-issue for most.
     
  5. gixxerwimp

    gixxerwimp Professional tricycle rider

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    I used the method from http://www.zen22142.zen.co.uk/Theory/inzoz.htm and used a 440Hz tone from http://onlinetonegenerator.com
    It wasn't too difficult, but requires a voltmeter than can measure very low voltages (the average DMM from Da Shack ain't gonna cut it).
     

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