TLV61048: Poor transient response with 1MHz operation

Steve Fenwick1

Part Number: TLV61048

For a TLV61048 configured to run at 1MHz, 3.5V to 6V, I'm seeing poor transient response. I suspect the output cap; it's a C3216X5R1E336M160AC (see attached). The SRF is right about at the switching frequency.

Comments?

C3216X5R1E336M160AC.pdf

over 4 years ago

0 Zack Liu over 4 years ago

TI__Mastermind 34231 points

Hi Steve,

Could you share the waveform of transient response? Thank you.

0 Steve Fenwick1 over 4 years ago in reply to Zack Liu

Prodigy 250 points

Trying to get plots for you.

Are you saying it's not generally incorrect for the output cap of a boost regulator to have a SRF lower than the operating frequency of the regulator? I'm looking at TI app note SLTA055.

Thanks!

0 Zack Liu over 4 years ago in reply to Steve Fenwick1

TI__Mastermind 34231 points

Hi Steve,

It's better to put a ceramic capacitor with its SRF higher than operating frequency of the regulator so the ripple would be smaller, and SW ringing during switching would be smaller.

Please share the schematic and transient waveform. Thank you.

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TLV61048: Poor transient response with 1MHz operation