TPS65100: Ringing at SW node

Francis Trinh

Prodigy 30 points

Part Number: TPS65100

Hi,

Please, advise what need to be changed to remove the ringing at the SW node.

Thanks

Francis

over 1 year ago

0 Liaqat Khan over 1 year ago

TI__Mastermind 18550 points

Hello ,

Connection of the switch node in your schematics is not correct. Switch node (pins 5 and 6) need to be connected to where you are pointing with the red arrow i.e. pins 5,6 should be connected at the junction of boost inductor and diode. Please refer to typical application schematics in the datasheet for proper connectivity.

Kind Regards,

Liaqat

0 Francis Trinh over 1 year ago in reply to Liaqat Khan

Prodigy 30 points

Hi Liaqat,

This Schematics was wrong, and I reworked the board to have SW node (pins 5 and 6) connected at Diode Anode pin. The ring that I captured is there with the correct device application connectivity.

Please, advise.

Thanks

Francis

0 Liaqat Khan over 1 year ago in reply to Francis Trinh

TI__Mastermind 18550 points

Hi Francis,

I don't see anything else wrong schematically related to this so I think that this ringing could be related to suboptimal board layout, especially given that you are blue wiring the switch node which has fast rise and fall times.

Kind Regards,

Liaqat

0 Francis Trinh over 1 year ago in reply to Liaqat Khan

Prodigy 30 points

Hi Liaqat,

Do you think snubber RC at SW node would help it?

Thanks

Francis

0 Liaqat Khan over 1 year ago in reply to Francis Trinh

TI__Mastermind 18550 points

Hi Francis,

Yes, you can experiment with various RC snubber values and they may help reduce the ringing but board layout is still an important factor to consider.

Kind Regards,

Liaqat

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TPS65100: Ringing at SW node