LM5148-Q1: LM5148-LM25148DESIGN-CALC - Buck Inductance

Constance Lauby

Part Number: LM5148-Q1
Other Parts Discussed in Thread: LM5148, LM5149

Hello,

I'm currently using the LM5149-LM25149 Calculator for the LM5148 Buck Converter (as the LM5148 one's is not available).

For the buck inductance calcul, I followed the datasheet of the LM5149 : Lo = Vout/(Delta_ILo*F_SW) * (1-Vout/Vin)

I don't find the same result as the one obtained in the calculator. Which formula is used in the calculator ?

Thank you in advance for your help,

Best regards,

+1 Orlando Murray 7 months ago

Hi CL,

The ideal inductance in the quickstart is calculated by the slope compensation equation, equation 9 in the datasheet.

Slope compensation is most important for duty cycle > 50%, or when VOUT > 0.5 VIN.

Otherwise then buck ripple percentage should be the design guideline.

Hope this helps,

-Orlando

0 Constance Lauby 7 months ago

Hello Orlando,

I understand now, thank you for your help.

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