• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 30 subscribers
  • Views 3578 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TAS5713 - Startup sequence

Erik Lundh
Prodigy 200 points
Other Parts Discussed in Thread: TAS5713, TAS5711, TAS5162

Hi!

I'm planning of using a TAS5713 in a project of mine and have a question about the startup sequence:

Why do you need to raise the PVDD after DVDD and what happens if you don't?

 

Greets,

Erik

  • 0
    TI__Mastermind 33420 points

    Hello Erik:
    This is a cut-paste error from previous data sheet.  In TAS5713, it does not matter.

    Best regards,

    Tuan

  • 0 in reply to Tuan
    Prodigy 200 points

    Okay, so what would the correct startup sequence be in that case? The same but without the last part with raising the PVDD?

    And a bit of curiosity, what previous data sheet? =)

    Thanks,

    Erik

  • 0 in reply to Erik Lundh
    TI__Mastermind 33420 points

    Hi Erik:

    You don't need to follow the power sequence on PVDD.  It can be up any time after 3.3V is good.  The last data sheet was TAS5711.

     

    Best regards,

    Tuan

  • 0 in reply to Tuan
    Prodigy 200 points

    So the correct startup sequence should be:

    1. DVDD power on

    2. Set PDN High

    Wait 100us

    3. Set RESET High

    and then start the setup with I2C

     

    Thanks again,

    Erik

  • 0 in reply to Erik Lundh
    TI__Mastermind 33420 points

    Between Reset high and writing to I2C registers, there should be a wait ~13.5mS.

    Also, please don't forget to turn on PVDD at some point.  PVDD powers on the amplifier section.

     

    Best regards,

    Tuan

  • 0 in reply to Tuan
    Prodigy 20 points

    My experience with the TAS5162 (another Class-D amp) is such that
    the DVDD must always come up before the PVDD. If PVDD is powered up
    first there will be a large amplitude (>45V, <2uS in my case) spike
    which will create a turn-on pop transient in the speakers.
    The spike is not concurrent with PVDD ramp-up but instead
    concurrent with DVDD ramp-up.

    Fortunately for my design both my DVDD and PVDD were under uC
    firmware control. This would have been unfortunate if I were using
    PVDD to generate DVDD by way of a step-down regulator.

    Also, always employ a bleed-off resistor (maybe 150K, 1/2W) in
    parallel with the PVDD capacitors. This way if the user turns off
    the amp and then turns it on again after <1 minute the residual
    charge will not cause a turn-on pop transient.

    It seems that somehow the DVDD powered logic circuitry "holds
    down" the power MOSFETS in the power bridge circuitry.