TPS56C215: max output capacitance limit

Sam Ting

Expert 3600 points

Part Number: TPS56C215

Hi team,

We found the recommended max. output capacitance is 500uF in datasheet.

Is there any potential risk if the application output capacitance exceeds 500uF? Thanks!

Best regards,

Sam Ting

over 6 years ago

0 Sam(MPAA) Zhang over 6 years ago

TI__Mastermind 19080 points

Hi Sam,

It depends. If all the output capacitance is formed by MLCC, which has very low ESR value, then too large output capacitance may lead to loop instability. If you are using electrolytic cap, I think it should be good.
Thanks!

Regards,
Hao

0 Sam Ting over 6 years ago in reply to Sam(MPAA) Zhang

TI__Expert 3600 points

Hi Hao,

Could you please explain more why too large output capacitance may lead to loop instability? Thanks for your support!

Best regards,
Sam Ting

0 Sam(MPAA) Zhang over 6 years ago in reply to Sam Ting

TI__Mastermind 19080 points

Hi Sam,

The output capacitance will affect the LC double pole in frequency domain. Large capacitance result in lower double pole frequency. The loop may not have enough phase margin to keep it stable. Thanks!

Regards,

Hao

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TPS56C215: max output capacitance limit