TPA3138D2: EMI countermeasures

Shuji Ishiwata

Mastermind 8880 points

Part Number: TPA3138D2

Hi All,

I have a question about the TPA3138D2PWP.

I've connected a ferrite bead and an inductor in series to OUTx to improve EMI.

I'm concerned about the heat generated by the ferrite bead in this configuration, but are there any other issues?

Or is it not recommended?

Best Regards,
Ishiwata

4 months ago

0 Wenbin Li1 4 months ago

TI__Expert 8610 points

Hi Ishiwata,

usually, bead and LC will chose only one. what's the purpose to use both?

Br,

Wenbin

0 Shuji Ishiwata 4 months ago in reply to Wenbin Li1

Mastermind 8880 points

Hi Wenbin,

Thank you for your reply.

The background is that the customer is currently using 1SPW mode, and it appears to have high EMI.
As a countermeasure, ferrite beads were added, but this did not significantly improve the situation.
Furthermore, adding an inductor improved the EMI.

Therefore, I would like to investigate the problems that arise when ferrite beads and inductors are connected in series.

Best Regards,
Ishiwata

0 Wenbin Li1 4 months ago in reply to Shuji Ishiwata

TI__Expert 8610 points

Hi Ishiwata,

if you are using LC filters, there is no need to use bead at the same time. LC only can resolve the EMI issue I think.

Br,

Wenbin

0 Shuji Ishiwata 4 months ago in reply to Wenbin Li1

Mastermind 8880 points

Hi Wenbin

In reality, customers are confirming the effectiveness through evaluation.

Is it not recommended to connect the beads and inductor in series?

Please help us solve the customer's problem.

Best Regards,
Ishiwata

0 Wenbin Li1 4 months ago in reply to Shuji Ishiwata

TI__Expert 8610 points

Hi Ishiwata,

I never see customer use it like this. it's duplicated.

Br,

Wenbin

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TPA3138D2: EMI countermeasures