LM5020: LM5020 Slope Compensation calculation formula

Peter Christen

Part Number: LM5020

Hi TI team

I would like to know the formula for additional external slope compensation with a LM5020MMX-1 in SEPIC topology and with coupled inductors. I wonder, which value of inductivity I have to use?

Best regards,
Peter

over 5 years ago

0 Yinsong Cai1 over 5 years ago

TI__Expert 7450 points

Hi Peter,

Thank you for your interest in LM5020.

The inductance used for slope compensation would be the inductance of the coupled inductor.

The coupled inductor used in Sepic is usually tightly coupled so the inductance is effectively doubled for the slope. However, the current slope at the switch is two times the single current slope for each of the inductor. Considering both effects cancel out, the inductance value equals the that of the coupled inductor.

Please let me know if you have any questions.

Thanks,

Yinsong

0 Peter Christen over 5 years ago in reply to Yinsong Cai1

Prodigy 40 points

Dear Yinsong,

Thank you very much for your fast response. The answer helps me to solve my issue.

Best regards,
Peter

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LM5020: LM5020 Slope Compensation calculation formula