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Ternary Modulation of PWM Generator + Power Stage

yoshiki hasebe
Mastermind 6385 points
Other Parts Discussed in Thread: TAS5558, TAS5624A, TAS5538, TAS5352, TAS5624, TAS5768M, TAS5754M, TAS5352A, TAS5342A

Dear Sirs,

My customer is using the TAS5558 + TA5624A.
They consider TernaryModulation but do not be able to operate.
Do TernaryModulation is possible with a combination of TAS5558 + TAS5624A?
Data sheet of the TAS5558 has described TernaryModulation.

In addition, they are saying to me that can do TAS5538 + TAS5352.
Do TernaryModulation is possible in this combination?
If possible, please tell me the above setting method.

Best Regards,

Y.Hasebe

  • 0
    TI__Expert 3110 points

    Hi Hasebe-san,

    I would not recommend using the TAS5538 as we do not support that device anymore. The TAS5558 will support ternary modulation and you should be using that instead.

    The TAS5624A should in theory support ternary modulation. I cannot guarantee any performance numbers on this as ternary modulation was not around when the device was created. The TAS5624A has not been tested using ternary modulation, but in theory any device that can operate in BD mode should be able to accept ternary modulation. The TAS5352

    To place the TAS5624A in the appropriate 2-ch BD mode for ternary modulation you should have the following logic on the mode pins:

    M0 = 0

    M1 = 1

    M2 = 0

    To place the TAS5352 into 2 channel BD the mode pins should be set like the following:

    M0 = 0

    M1 = 0

    M2 = 0

    To enable ternary modulation on the TAS5558 you should set Reg0x25 to A0h. (bit 5 needs to be 1)

    Regards,
    Mike Ulrich 

  • 0 in reply to Mike Ulrich
    Mastermind 6385 points

    Hello Mike-san,

    Thank you for your reply.

    We knew that TAS5538 is unused device.

    So our customer are using TAS5558.

    Our customer has tried the Ternary Mode in TAS5558 + TAS5624A.
    But it did not work.
    Also, we were tried in at TAS5538 + TAS5624A here but it was the same.
    (It is in the combination of you and TAS5538 + TAS5624A obtain the current EVM)

    Therefore, even when currently available of EVM is TAS5538 are mounted, we ask you a question.

    They have implemented the M0, M1, M2 set of TAS5624A.

    Also,they seem to have carried out previously in relation to TAS5352 TernaryMode.
    But I do not know yet more information.

    Please tell me how to operate the TernaryMode by (TAS5558 + TAS5624A) .

    Do you know the combination can operate the TernaryMode (TAS5558 +?)?

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    TI__Expert 3110 points

    Hi Hasebe-san,

    I am still looking into this. It will take some time as I am not 100% sure the TAS5624 can handle a ternary signal since this part was not designed to be used that way.

    Regards,
    Mike UIrich

  • 0 in reply to Mike Ulrich
    Mastermind 6385 points

    Hello Mike-san,

    Thank you for your reply.

    I understand.

    I  will wait for your reply.

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    TI__Expert 3110 points

    Hello Hasebe-san,

    I was unable to get the TAS5624 to accept the ternary signal. The output after the TAS5624's output filter looks like the following:



    I have tried multiple ways to correct this behavior but have had no success. I have concluded that the TAS5624 does not support the ternary signal on the input.

    Regards,
    Mike Ulrich

  • 0 in reply to Mike Ulrich
    Mastermind 6385 points
    Hello Mike-san,

    Thank you for your reply.

    I understand your answer.
    I will answer to our customer .

    By the way , I have 1 more question.
    Do you know any other combination capable of realizing Ternary Mode (other PWM generator + other Power stage)?

    Best Regards,
    Y. Hasebe
  • 0 in reply to yoshiki hasebe
    TI__Expert 3110 points
    HI Hasebe-san,

    TAS5754M and TAS5768M are two amplifiers that will accept a ternary input. They are not high powered like the TAS5624. The TAS5558 would work fine as a modulator.

    Regards,
    Mike Ulrich
  • 0 in reply to Mike Ulrich
    Mastermind 6385 points
    Hello Mike-san,

    Thank you for your quick reply.

    I understand your suggestion.
    So I've already proposed to the customer.
    But, he has a design in the configuration of the separate PWM generator and Powerstage.
    Therefore, he does not need a device of 1chip device.
    He needed a PowerStage device that can be configured with the TAS5558.

    Do you have other solutions?

    Best Regards,
    Y.Hasebe
  • 0 in reply to yoshiki hasebe
    TI__Expert 3110 points
    Hi Hasebe-san,

    Any of our open loop devices should be able to handle Ternary. I would suggest you use the TAS5352A . The issue with the waveform I posted above comes from the closed loop devices.

    Just curious, what is the customers key reason for using ternary modulation?

    Regards,
    Mike Ulrich
  • 0 in reply to Mike Ulrich
    Mastermind 6385 points
    Hello　Mike-san、

    Thank you for your reply.
    Our customer wants to use the Ternary Mode in order to reduce the audible band noise.

    Off course,we have recommended the AD mode.
    They were using the old days Ternary Mode, but there is no experience with the new device .
    Therefore, they have been asked for the means for realizing the Ternary Mode with the new device to me.

    So do you have setting for TernaryMode of the TAS5352A a combination of tas5558 + TAS5352A? Or Not?

    In addition,
    How about TAS5342A?
    When I checked detasheet , it seems as same series to TAS5352A.

    Best Regards,
    Y. Hasebe
  • 0 in reply to yoshiki hasebe
    TI__Expert 3110 points
    Hi Hasebe-san,

    I do not have the exact settings to give you since these parts were not designed with ternary in mind. However, the part suggestion does come from our systems guy who designed the chip.

    Regards,
    Mike Ulrich
  • 0 in reply to Mike Ulrich
    Mastermind 6385 points

    Hello Mike-san,

    Thank you for your quick reply.

    I will tell our customer this information.

    Best Regards,

    Y. Hasebe