TPS55340EVM-017: High output ripple for EVM..

Peter Tseng

Mastermind 6380 points

Part Number: TPS55340EVM-017

Dear Sirs,

The customer is testing TPS55340EVM and found the output voltage ripple is too high.

The Vin=7.2V and Vout=24V, Iout=0.5A

Below is the scope waveform for reference.

The ripple voltage is around 1.3V.

May I have your suggestion on how to reduce the ripple?

Thanks.

over 4 years ago

+1 Stefan Schauer over 4 years ago

TI__Guru 61011 points

Hi Peter,

it looks like the customer is using a standard Oscilloscope probe, which just picks up lot of noise from the switch node.

Please check how they are measuring and if they are using the recommended tip and barrel method to capture this signals.

Also enabling the 20MHz bandwidth filter in the scope would be good to further suppress injected noise into the probe (sense to GND loop)

See:

EETimes - Power Tip #6: Accurately Measuring Power Supply Ripple

Engineer It - How to test power supplies - Measuring Noise | TI.com Video

Best regards,

Stefan

+1 Stefan Schauer over 4 years ago in reply to Stefan Schauer

TI__Guru 61011 points

Hi Peter,

I have not seen an update on this thread for the last 10 days.
Maybe you could solve this issue already in the meantime, in this case it would be great to press the is solved button.
If there is still something open, just let me know with the new details.

Best regards,

Stefan

0 Peter Tseng over 4 years ago in reply to Stefan Schauer

Mastermind 6380 points

Hi Sir,

The test result is OK!

Problem fixed.

Thanks.

Power management

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TPS55340EVM-017: High output ripple for EVM..