Hi all,
I have used the IC "LM5148-Q1" for the design of the buck converter, where I have calculated all the values according to the IC datasheet also verified with the support Excel file provided. Every thing looks good according to the calculation but I have an re-occurring issue that the converter output voltage is dipping with the addition of the load. the line regulation is fine i.e., at a fixed load the voltage variation is minimal but for different loads the output voltage is changing.
Here are my design considerations:
Input Voltage range : 40V - 60V
Output Voltage : 13.8V
Output Current : 10A (Max load)
Switching Frequency : 500kHz to 600kHz
Inductor Current Ripple : 25% of Max output current
I am trying to find the losses at different load conditions but they are not matching the theoretical losses, so I went through the "SYNC-BUCK-FET-LOSS-CALC MOSFET power loss calculator for synchronous buck converter applications" Losses calculation Macro sheet. But I am not able to get the MOSFET selection correctly, even though I am choosing the voltage as 80V (input Voltage).
Input parameters:
But the appropriate MOSFET selection is not available. Can you please guide through how to get the proper MOSFET selection.
Thanks
Mahankali Nikhilindu Kasyap