MP3423 and MP3426 Simulation Question

DC-DC Power Converters
1

Hi everyone,

For a project I need to use a boost converter to power a raspberry pi 4 from a li-ion battery. The li-ion battery is 3.7 nominal voltage and the raspberry 4 needs 5V. I chose the MP3423 to do this project, however, I need to turn in a simulation (and I cant simulate the MP3423 on MPsmart so I chose to simulate a similar component MP3426). I ran the simulation and I am getting an output of 5V however, I am not sure how to estimate how much resistance is an raspberry pi (I just put 100ohms because I tested various values) , so I can verify the current output.

Either way, if my load is a raspberrypi 4, would I even be able to get a current of 3A from this chip?

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2

First approximation, Vout is 5V and 3A 15W lets say the converter is 100% efficient so that Pin = Pout if Vin is 3.6V and Pin is a5W then Iin is 4.2A . Referring to the data sheet, we see at 50% duty cycle ( about where you will operate) the switch current limit is over 6A. So pulling 4.2A average from the input is plausible. You might want to check out Coilcraft website they have a nice DC DC design aid ( intended to sell their inductors) but it will give you a quick calculation of the inductor average and peak currents.