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Does TS3A226AE support high impendance microphone (like IPhone 6 earphone ) ? (this post also explains the how the TS3A226AE audio jack detection works)

daniel
Genius 5095 points
Other Parts Discussed in Thread: TS3A226AE, TS3A227E, TS3A225E

Hi,

My customer concerns about TS3A226AE can support high impendance microphone or not.

They got information that the microphone of IPhone 6 earphone has higher impedance than others, but they didn't know the actual impedance value.

Do you have experience on this application? Or high impedance microphone support case.

Thanks

  • 0
    TI__Mastermind 45495 points
    Daniel,

    Short answer is yes the TS3A226AE will support the Iphone 6 earphone. I am working on a more complete answer in the next couple of days.

    Thank you,
    Adam
  • 0 in reply to Adam Torma
    Genius 5095 points
    Dear Adam,

    Are there any further answers for the application of Iphone 6 earphone?
    And we have another question:
    Does TS3A226AE Audio Switch also support iphone 6 earphone for volume key ?

    Thanks
    Daniel
  • 0 in reply to daniel
    TI__Mastermind 45495 points

    Daniel,

    The TS3A226AE compares the resistance between the tip and Ring 2 (R2)  and the resistance between tip and sleeve (Rsleeve).

    If the resistance R2 = Rsleeve than the device will detect 3-pole

    If the resistance R2 < Rsleeve than the device will detect Standard

    If the resistance R2 > Rsleeve than the device will detect OMTP

    The higher resistance does not matter in this case because of the logic described above.

    The TS3A226AE will support iphone6 earphone MIC detection as long as the resistances R2 and Rsleeve fit into the logic described above.

    The TS3A226AE does not have key press deteciton support.  Please look at the TS3A227E audio jack switch with key press detection.

    Thank you,

    Adam

  • 0 in reply to Adam Torma
    Expert 2056 points
    Just to clarify: These are DC resistances, not AC impedances, and they have to be within the ranges shown (2 kΩ and 4 kΩ) in order to be detected?
  • 0 in reply to Jonathan9420
    TI__Mastermind 45495 points
    Yes, diagrams above are referencing common DC resistances found in some example audio plugs and not an AC impedance. The absolute value of the resistances is less important than how the R2 and Rsleeve resistances compare to each other.

    If the resistance R2 = Rsleeve than the device will detect 3-pole

    If the resistance R2 < Rsleeve than the device will detect Standard

    If the resistance R2 > Rsleeve than the device will detect OMTP

    Thank you,
    Adam
  • 0 in reply to Adam Torma
    Expert 2056 points
    So if R2 were 100k and Rsleeve were 102k, for instance, it would still detect it?
  • 0 in reply to Jonathan9420
    TI__Mastermind 45495 points

    Jonathan,

    The TS3A226AE behaves similar to the TS5A225E.  If you look at the TS3A225E datasheet register map you can see that the device recognizes a range of resistances and assigns it a register value.  The device then compares the register values to determine if the tip to sleeve (Rsleeve) and tip to ring 2 (R2) resistances are >, <, or = to each other.  

    In the case you mention R2 = 100k ohms compared to Rsleeve = 102k ohms the audio jack devices will measure those resistances and place them both in the >2800 ohm bucket. Since both resistances will be in the same bucket the audio jack will determine the resistances are equal and configure itself for a 3 pole device grounding both the sleeve and ring 2.

    Thank you,

    Adam