LMZM33603EVM: spike noise

user5347034

Part Number: LMZM33603EVM

Hi team members.

I measure noise with LMZM33603EVM.

The spike noise voltage is higher when the output noise is measured at both ends of the C10 pad than when measured at both ends of the C5.
Why is this?

over 5 years ago

0 Denislav Petkov over 5 years ago

TI__Mastermind 19891 points

Hello,

It is possible that you are picking up noise with your probe ground loop. Having some ground loop on the probe close to the switcher can pick up additional noise. The C10 pads are further away from the switcher and the noise pickup will be less.

Could you share a picture of your measurement technique?

Also you can try tilting the probe at a different angle when you are measuring at the C5 capacitor and see if that changes the measurement result. This will give you some idea if you are picking up radiated noise.

Cheers,
Denislav

0 user5347034 over 5 years ago in reply to Denislav Petkov

Intellectual 320 points

Hello, Denislav

Thank you for your reply.

I was careful about the ground loop and kept the GND loop as small as possible. But I was not careful about the angle to measure.

I will change the angle to measure.

Regards

0 Denislav Petkov over 5 years ago in reply to user5347034

TI__Mastermind 19891 points

Hello ,

Did you experiment with the measurement any further?

Please, let us know if you need any additional help.

Cheers,

Denislav

0 user5347034 over 5 years ago in reply to Denislav Petkov

Intellectual 320 points

Hello, Denislav

Thank you for your reply.

As a result of the examination, the tendency of the noise to be greater in the far place did not change.

I decided to add a filter to the output.

Regards.

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LMZM33603EVM: spike noise