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LM5155EVM-BST: Input operating range

Part Number: LM5155EVM-BST
Other Parts Discussed in Thread: LM5155

Hi Team,

My customer is trying to evaluate using LM5515EVM.

However, 6V is the minimum value for Vin of LM5155EVM-BST.

The input operating range of the LM5155 is 3.5-V to 45-V Operating Range, so I think it can be used even with Vin = 3.7V.

Is it possible to operate with Vin = 3.7V, Vload = 24V, Iload = 1.5A by remodeling EVM?

I did a simulation with Webench.

I was able to obtain a circuit diagram similar to EVM.

Therefore, we believe that it is feasible by changing the EVM component constant.

Best Regards,


  • Hi Kenji,

    Thank you for reaching out.  The EVM's 6V is limited by (1) the UVLO setting,  (2) onboard peak current limit,  (3) MOSFET power dissipation. 

    Yes it can support 3.7Vin to 24Vload, but not 1.5A as it will hit the peak current limit. Yes you can reduce the current sense resistor to allow more current, but you should also pay attention to the MOSFET dissipation, as well as the inductor Isat and power dissipation.  Basically you may need to change a few power components.

    Please use the online design calculator for new part selections.


    Youhao Xi, Applications Engineering