LM5088: On the operation of the LM5088

Masazumi Ishii

Part Number: LM5088

Hello.

We are considering LM5088.
We are evaluating the circuit designed using WEBENCH by modifying the EVM.
However, there are ambiguous moving parts in the evaluation, and I will make inquiries.

For details, please check the attached document,

Thanking you.3005.LM5088.pdf

LM5088-50-2 (1).pdf

over 7 years ago

0 David Baba over 7 years ago

TI__Mastermind 40040 points

Hello Masazumi,

I looked over the waveform and they do not look correct? There appears to be some instability. Did you install the WEBENCH Components into the EVM? Or were compromises made, if so, which ones? Thanks.

David.,

0 Masazumi Ishii over 7 years ago in reply to David Baba

Genius 3945 points

Hello.

I described in the separate sheet about the change of LM 5088 EVM.
When output is 50 V Please tell me about cause for unstable operation.
Details will be attached

thank you.LM5088out35.pdf

0 David Baba over 7 years ago in reply to Masazumi Ishii

TI__Mastermind 40040 points

Looking at the Tan delta of Couts and calculating back to ESR, shows a very high ESR? Can you place in Couts that have a lower ESR, say 100mR. I believe the high ESR and low Frequency Zero is causing instability due to the high Cross over frequency?

If you dont have any other Cout capacitors to try, suggest decreasing Rcomp from 44.2k to 5k.

Hope this helps?

David.

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LM5088: On the operation of the LM5088