TPA3130D2: TPA3130D2

user4917604

Prodigy 110 points

Part Number: TPA3130D2

Hi,

Please help me regarding D-Class AMP_TPA3130D2 pop noise, Please find Attached pdf file.

We designed Audio AMP and use datasheet's reference design on P26 as a post filter

and almost the same connection SDZ FALUTZ as this.

The result is that No POP noise at Power rise but there is another POP noise

at the moment of mute function disabled.

Probably LC rapid and big charging current caused POP noise,( it seems that PWM output is DC,)

Is it possible to make 50% duty PWM output when mute enabled or something else

to reject POP noise?

Regards,

TIQA.pdf

over 7 years ago

0 Shawn Zheng over 7 years ago

TI__Mastermind 24835 points

Takeuchi-san,

Thanks for asking questions in E2E. After reviewing the result and SCH, I have the following suggestions:

1. The proper procedure for power-on is as following. Unmute is enabled after SDZ is pulled up(in Stage3 and Stage4). The dealy needs to be larger than 40ms. In the SCH, we can't see the delay from the SCH.

2. Try to use C13, C14, C19, C20 with 1uF instead of 10uF. The pop amplitude should be reduced.

3. The input is in single-end mode. If use differential input mode, the pop could be much better.

Best regards,

Shawn Zheng

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng san,

Thanks for your kind and easy to understand feedback.

We try suggestion #1 first and let me inform you the result later.

This is just a quick note.

Best Regards,

Takeuchi

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng san,

Thanks for your support.

We try your suggestion #1, But POP noise still remain.

And we evaluate furthermore the signals after and before D-AMP

for your information. Please find attached pdf file

It seems that POP noise happens D-AMP LC post-filter.

suggestion #2 still effective?

Best Regards,

Takeuchi

0 user4917604 over 7 years ago in reply to user4917604

Prodigy 110 points

POPNOISE.pdfSorry, I may miss to attach pdf file

0 Shawn Zheng over 7 years ago in reply to user4917604

TI__Mastermind 24835 points

HI Takeuchi-san,

I guess you are using 1SPW mode, right? You can try to use BD mode.

I think the SCH which you shared to me is for simulation, and some pins are not shown. Could you please send me the original SCH?

Best regards,

Shawn Zheng

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng-san

Thank you for your quick reply.

We use BD mode.. please find attached SCH.

We're happy if you aware something.

Best regards,

Takeuchi

0 Shawn Zheng over 7 years ago in reply to user4917604

TI__Mastermind 24835 points

Hi Takeuchi-san,

Thanks for you reply. Could you please try to use L=10uH and 1uH for the LC filter? I think 1nF is too small.

Best regards,

Shawn Zheng

0 Shawn Zheng over 7 years ago in reply to Shawn Zheng

TI__Mastermind 24835 points

Sorry for the typo, L=10uH and C=1uF for the LC filter.

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng-san

Thank you for your feedback.

your advise encourage us so much.

I'll try L=10uH and C=1uF for the LC filter

and other L&C variation, let me inform you later.

But I'm afraid that rush current happens whenever mute is enabled

from the point of circuit principles and caused pop noise.

and increase capacitor brings about resonant vibration, I'm afraid....

(please find pic)

How about IT's TPA3130D2 evaluation board?

Best Regards,

Takeuchi

0 Shawn Zheng over 7 years ago in reply to user4917604

TI__Mastermind 24835 points

Hi Takeuchi-san,

The recommended LC filter design for TPA3130D2 is as below.

The pop-click performance is quite good on our EVM, please refer to our EVM design at http://www.ti.com/lit/ug/slou341a/slou341a.pdf

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng-san

Thank you for your feedback.

We'll try the circuit described figure above,

removing Snubber circuit.

Best Regards,

Takeuchi

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng-san

Thank you for your feedback.

I tried 10uH/0.68uF LC filter but the conclusion is the same...

I also tried your 1'st advise reducing 10uF input capacitor to 1uF.

and Pop noise become slightly small.

So it seems that something is wrong with D-AMP input circuit's

impedance or something. RINP connects 10uF & 100kohm VR,

and RINN connect 10uF only. It causes POP noise?

Best Regards,

Takeuchi

0 Shawn Zheng over 7 years ago in reply to user4917604

TI__Mastermind 24835 points

Hi Takeuchi-san,
It's very strange. If the pop is caused by input, then the right sequence on MUTE and SDZ can avoid pop, because the output is muted when input is setting up. Could you please double-check your power-up sequence?

Best regards,
Shawn Zheng

0 user4917604 over 7 years ago in reply to Shawn Zheng

Prodigy 110 points

Hi, Shawn Zheng san,

Thanks for your feedback.

We successed to remove POP noise in the condition as below

1, reduce input capacitor 10uF to 1uF (your 1'st suggestion)

2,use ferrite bead instead of LC filter

We' re not for sure why LC filter is not good, WE74279252 is optimum or not,

But We're happy if this result would helps you and other TPA3130 user.

and for your info, Power up sequence is OK as below,

Thank you for your help again.

Best Regards,

Takeuchi

0 Shawn Zheng over 7 years ago in reply to user4917604

TI__Mastermind 24835 points

Hi Takeuchi-san,

I really admire your ingenuity and creativity. And I also learned a lot from you and your project. Enjoy the beautiful music!

Best regards,

Shawn Zheng

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TPA3130D2: TPA3130D2

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