LM5157-Q1: SEPIC WEBENCH simulation

Koji Ikeda

Part Number: LM5157-Q1
Other Parts Discussed in Thread: LM5157, LM5156H, LM5156

Hello support team,

Customer would like to do WEBENCH simulation for LM5157 SEPIC design, however, WENECH does not support it. Do you have any plan to support?

I found WEBENCH can support LM5156H SEPIC design, can they adopt this LM5156H simulation result to LM5157, except FET design?

Thanks,

Koji Ikeda

over 3 years ago

0 Yinsong Cai1 over 3 years ago

TI__Expert 7450 points

Hi Koji,

Yes, they can use the LM5156 webench for the basic simulation. But note that they need some additional check.

1. SW and VIN max voltage.

2. Peak current limit

3. Slope compensation

Please let me know if they have any question.

Thanks,
Yinsong

0 Koji Ikeda over 3 years ago in reply to Yinsong Cai1

TI__Expert 5595 points

Yinsong-san,

Thank you very much for your support. For #3, could you advise how to consider slope compensation and external shunt resister on LM5156H, when they adopt LM5156 WEBENCH result into LM5157 design?

Thanks,

Koji Ikeda

0 Yinsong Cai1 over 3 years ago in reply to Koji Ikeda

TI__Expert 7450 points

Hi Koji-san,

In LM5156 and LM5156H, there is a internal Vslope 40mV and an external Islope 30uA. By adding the slope resistor externally, the additional slope voltage can be implemented.

In LM5157, there is only the internal Vslope 500mV and no external Islope. This information can also be found in the datasheet.

Please let me know if there is any question.

Thanks,

Yinsong

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LM5157-Q1: SEPIC WEBENCH simulation