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LM5002: Questions about LM5002 SEPIC circuit.

Part Number: LM5002

Hello guys,

One of my customers is considering using LM5002 or similar device for their new products.

Their requirements about power supply input/output are the follows.

Vin=15V~28V, Vo=24V or 48V, Io=0.1A at both voltages.

They want to change the output voltage (Vo) with feedback resistor ratio changing only without peripheral parts

(L, C, compensation R and C etc) changing.

Is it possible to generate 24V or 48V with feedback resister ratio changing only?

If it is yes, could you please give me how to determine each part parameter?

They couldn't generate those part parameters by Webench.

Your reply would be much appreciated.

Best regards,


  • Hello Kazuya,

    For the SEPIC configuration we do not have a Webench model of this device. 

    A starting point could be the 24V circuit in the datasheet.

    I wonder why the customer wants to use a SEPIC converter for 48V.

    Best regards,

  • Hello Brigitte,

    Thank you very much for your reply.

    It is very helpful for the customer and me.

    They want to use LM5002 for both of 24V and 48V output without peripheral parts and topology changing 

    except the feedback resister changing. Also they want to change the feedback resistor

    by a FET controlled by MCU port output.

    They need to use SEPIC for 24V output because Vin range is 15V~28V. 

    So they don't change the topology.

    Anyway, thank you again for your reply.

    Best regards,