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TPA6100A2 mute control

KANJI SHIBATANI
Mastermind 6205 points
Other Parts Discussed in Thread: TPA6100A2, TPA6133A2, TPA6138A2

 

Hello

My customer has just started ES of their headphone using TPA6100A2, and they

intend to use /SHUTDOWN as a mute control.

*Customer let /SHUTDOWN held low before ~ 10ms  VDD goes low. 

*Schematic is just same as data sheet page 1 ,Co=100uF Ci=1uF.

However, audio signal is muted after  ~20ms of /SHUTDOWN goes low,  and there are pop noise.

I'd attached  the waveform.

Q1

Do you think /SHUTDOWN can be used as a audio mute?

If yes, do you have a recommended power off sequence  of  /SHUTDOWN and VDD?

Q2

As per customer's result, mute of audio signal by /SHUTDOWN  delays ~ 20ms .

Is  this inherent issue of TPA6100A2 ?

Q3

Do you have any recommended device in place of TPA6100A2?

 

I'm sorry that I don't have  EVM and I did not tested myself....

II would like to have your advise

Best Regards

 

 

 

 

 

 

 

 

 

 

 

  • 0
    TI__Guru** 102065 points
    Hi Shibatani-san,

    What are the resistor values for your setup? Could you share a schematic?
    Have you followed the equations given in the D/S to select the components? These equations must be used for a good performance.
    There are newer headphone drivers like the TPA613x and TPA614x families. You can also use the audio selection tool at the TI website and look for devices that match with your application needs. TPA6133A2 for example shows a better shutdown time in its specs.

    Best regards,
    Iván Salazar
    Texas Instruments
  • 0 in reply to Ivan Salazar
    Mastermind 6205 points

    Dear Salazar-san

    Thank you for your advice.

    I had asked customer to check the components value .

    It may be the value of Cb capacitor.

    Thank you and with my best regards.

  • 0 in reply to KANJI SHIBATANI
    Mastermind 6205 points

     

    Dear Salazar-san

    Customer had sent me the schematic. ( attached)

    (1)

    I think there are no problem for customer's schematic. Would you please give me your opinion

    for schematic?

    (2)

    I think  , in general, /SHDN pin of TPA6100A2 can NOT be used for mute control ,,, would you please

    let me know how do you hink about this?

    (3)

    I think there are no spec. for delay from SHUTDOWN in TPA6100A2 data sheet, so, mute delay( 20ms) from

    /SHDN  may be reasonable.

    How do you think?

    (4)

    If customer hope small POP in /SDN=Low, I think additional circuit may be necessary,

    like mute transistor circuit after the Cc ; output AC coupling ...

    If you had any idea for external mute control for TPA6100A2, would you please let me know?

     

    My customer is going to proceed next stage ( pre-production design), and he hope to

    have your advice.

    I hope your answer within 2 days,,,and I'm sorry to bother you again.

     

     

     

     

     

     

     

     

     

  • 0 in reply to KANJI SHIBATANI
    Mastermind 6205 points

     

    Dear Salazar san

    I forgot shematic,

    Sorry to bother you

    Thank you

     

    TPA6100A2_schematic.TIF

  • 0 in reply to KANJI SHIBATANI
    TI__Guru** 102065 points
    Hi Shibatani-san,

    The schematic capacitor and resistor values don't fit the equations (6) and (8) from the D/S. You may reduce the Ci to 1uF for example to fit the equations.
    I think the 20ms delay time is reasonable. Also I think the /SD delay time may not be ideal for a mute function.
    You can take a look at newer devices from DirectPath family like TPA6138A2; this part has mute function pin.
    Hope this help you.

    Regards,
    Iván Salazar
    Texas Instruments
  • 0 in reply to Ivan Salazar
    Mastermind 6205 points

    Hello Slazar-san

    Thank you for you advice!

    TPA6138A2 is smaller power than TPA6100A2, but I will ask customer to select this.

    Thank you and with my best regards