TAS2562: boost capacitor piezoelectric noise

cain.yen

Part Number: TAS2562

Hi,

The VBAT of our design has a ripple around 217Hz due to GSM communication, and tas2562 boost is disabled in this state so PVDD and VBST were measured almost the same with VBAT. But we also detected that the boost output capacitor is making audible piezoelectric noice. Since tas2562 is placed at a key point, the influence could be signifcant. We'd like to hear some suggestions on this issue.

Kind regards,

Cain

over 4 years ago

0 Luis Fernando Rodriguez S. over 4 years ago

TI__Guru* 84915 points

Hi, Cain,

We will take a look at this issue and will answer as soon as possible.

Best regards,
Luis Fernando Rodríguez S.

0 Ivan Salazar over 4 years ago

TI__Guru* 95225 points

Hi Cain,

One way to avoid piezo effect at the capacitors would be to use Tantalum instead of ceramic.
If this is not possible, you can try with the following option: https://product.tdk.com/en/search/capacitor/ceramic/mlcc/info?part_no=CGA5L1X7R1V106K160AC
Or use multiple capacitors like this one: https://product.tdk.com/en/search/capacitor/ceramic/mlcc/info?part_no=C2012X6S1C156M125AC

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

0 cain.yen over 4 years ago in reply to Ivan Salazar

Prodigy 80 points

Hi Ivan,

Thank you for your solution. However, it is less likely for us to apply Tantalum capacitor due to its reliability. We have placed two 0603 106/16V ceramic capacitors on PVDD and we might not use larger ones. We are thinking about making changes to the layout or TAS2562 configurations to reduce the noice to an acceptable level.

Kind regards,

Cain

0 Ivan Salazar over 4 years ago in reply to cain.yen

TI__Guru* 95225 points

Hi Cain,

We'll be releasing a layout guideline document for TAS2562 over the next month.
I'll reach out to you once we have released it.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

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TAS2562: boost capacitor piezoelectric noise