TAS5731M: TAS5731M bootstrap capacitor value

Yang Wu

Part Number: TAS5731M

Hi team.

In the EVM user guide of TAS5731M, I see the bootstrap cap is 0.0033uF. If it's OK to use 0.022uF、50V， X7R? How can you evaluate the capacitance is proper?

thanks a lot.

Best regards,

Yang

over 3 years ago

0 Sam(MPAA) Zhang over 3 years ago

TI__Mastermind 19080 points

Hi,

It's recommended to follow our recommendation to use a 33nF cap.

This the charge held by bootstrap cap is used to power the high side driver. The cap discharged when HS FET turns on and get re-charged when LS turns on. In hard clipping conditions, HS keeps ON in multi cycles, BST cap is needed to hold the voltage above BST undervoltage threshold to make the FET driver working well.

Regards,

Sam

0 Yang Wu over 3 years ago in reply to Sam(MPAA) Zhang

TI__Intellectual 2840 points

Hi Sam,

Got it. I will forward your suggestion to customer.

thanks a lot.

Best regards,

Yang

0 Xiaohui Gong over 3 years ago in reply to Sam(MPAA) Zhang

Prodigy 20 points

Hi Sam,

I know the function of the bootstrap, but I have no the 0.033uF in our material library. We have 0.022uF, X7R,50V or 0.047uF，X7R, 25V. If so, which on would you prefer to use?

Besides, if we pass the AUDIO performance, thermal test and EMI test using 0.022uF, can we use the 0.022uF,X7R,50V in MP stage?

Regards,

Xiaohui

0 Sam(MPAA) Zhang over 3 years ago in reply to Xiaohui Gong

TI__Mastermind 19080 points

Hi Xiaohui,

0.022uF should also be good.

Regards,

Sam

0 Xiaohui Gong over 3 years ago in reply to Sam(MPAA) Zhang

Prodigy 20 points

Thanks!

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TAS5731M: TAS5731M bootstrap capacitor value