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TAS5825MEVM: X-talk test

Part Number: TAS5825MEVM
Other Parts Discussed in Thread: TAS5828MEVM

Hi,

I tested the cross-talk for TAS5825EVM and found it worse than stated in the datasheet (100dB). Please check if my setup or test condition is proper for this test. Please advise the test condition for "x-talk" in the TAS5825 datasheet( PVDD? impedance connected to spk out1/2? etc)


Phenomenon: crosstalk test 55dB (TAS5825 datasheet: X-talk 100dB@1K)

Test DUT: PurePath Console Motherboard + TAS5825EVM

PurePath Console settings:

TAS5825_PVDD19V_EE test.zip

Connected I/O on PPC MB: Optical

PVDD: 19V by DC power supply

Measurement point: OUT1 & OUT2 with 4ohm dummy load connected

Signal: 1K_0dBFS and 1K_-20dBFS are send via APx525 optical

Test Result:

55dB

 Thank you!

  •  Hi Lin

    you can refer the crosstalk chart in our datasheet.

    we measured crosstalk value at different situation, for example: figure 7-18.

    BTW, the figure you attached is just a concept figure or the actual Mother board you use?

    the motherboard seems different with what we use. below link is what we are using now.

    https://www.ti.com/tool/PUREPATH-CMBEVM

    thanks.

    jesse

  • Hi Jesse,

    The attached picture is the actual mother board I  use for test. The PPC mother board is connected to the TAS5825MEVM.PurePathConsole+TAS5825MEVM

    The crosstalk test condition refer to "figure 7-18", do you mean the TAS5825MEVM datasheet? Is the crosstalk (55dB@1K) more related to the TAS5825MEVM?

  • Hi Christine

    Is the crosstalk (55dB@1K) more related to the TAS5825MEVM?

    Yes, we think so. The crosstalk is mainly related with two factors, one is the Amp's performance, another is the inductor. For our Amp, we test it with validation board, with better condition, the crosstalk is no problem, the same with datasheet curve. But if on the board, the inductor is not shielded, also put very close to each other, like EVM does. The magnetic field create by inductor will intercoupling, cause additional crosstalk. Our Amp have no way to remove this kind of crosstalk. We recommend our customer to use shielded inductor, or could put two channel's inductor far away from each other. That could solve the problem. 

  • Hi Shadow,

    Do you have test data about the TAS5825MEVM? 

    We recommend our customer to use shielded inductor, or could put two channel's inductor far away from each other. That could solve the problem.

    Can we have disign guide or suggestion about the distance between 2CH's inductor?

    Thank you,

    Christine

  • Hello Christine,

    We didn't have a specific design guide but for reference you can look at a similar device the TAS5828MEVM, which has an output layout more optimized for crosstalk.

    best regards,
    Luis