LM5116: There has some noise (frequency is about 1.6K) in the output voltage

Hope Chen

Expert 1030 points

Part Number: LM5116

1,SPEC:INPUT:30-80V; Output:9V/3A

2,The SCH and Output waveform is as below

3,Question：a: There has some noise (frequency is about 1.6K) in the output voltage

could you give some advise for the issue?

over 7 years ago

0 Ryan May over 7 years ago

TI__Genius 13700 points

Hello Hope,

That looks like a load induced transient event. Do you have any portion of your system that executes or performs some operation at the frequency?

0 Hope Chen over 7 years ago in reply to Ryan May

Expert 1030 points

Dear Ryan,
I will check it as soon as possible
Thanks a lot

0 David Baba over 7 years ago

TI__Mastermind 33200 points

Hello Hope,

Is this occurring at switching frequency? Can you take a scope shot of the Switch node also? Is the Switch node unstable?

If not, I would example how you are measuring Vout?

Need to use Short Ground lead and directly across Cout.

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LM5116: There has some noise (frequency is about 1.6K) in the output voltage