How to design a 3.7v to 5V 2A stepup circuit ?

Thread Starter


Joined Oct 16, 2017

Sorry for my bad english
I m working on a project using raspberry pi. I need to power Pi(800mA), 5 inch LCD(300mA), 500mA current for IR leds simultaneously. Total around 2 Amps current i need.I saw many modules available online. But i don't want to buy these modules, i want to design a circuit like this with minimum size.
Im using 3.7v 4000mAh li-ion battery as power source.

I saw many circuits.....Can anyone help me please for finding the best circuit.
Thanks in advance


Joined Jun 17, 2014

There are circuit boards you can use already built. Check Amazon, etc. Also watch efficiency and max current, get a current rating higher than you need by say 50 percent.


Joined Sep 24, 2015
At 1.6 amps (calculated from your figures) I'd recommend a supply that can deliver twice that much current. In other words I would want a supply capable of at least 3.2 amps. So 3.2 amps at 5 volts (3.2 X 5 =) 16 watts. If you had a "PERFECT" source of power (no losses due to efficiency) then 3.7 volts delivering 16 watts would require (16 ÷ 3.7 =) 4.3 amps capability. Your LI battery isn't capable of that much current. Now, your circuit (as has been pointed out) (and if it were a "Perfect" source) 1.6 amps (strictly holding to that number) would require (again a perfect source) 5 volts (times) 1.6 amps = 8 watts. 8 watts (divided by) 3.7 volts equals 2.16 amps.

What we're getting at is that your battery isn't going to deliver the performance you want. And I always question "Why build when you can buy?" OK, I understand, and practice this too - I build even though I can buy but I do so simply for the fun and experience of it all. So if you truly want to build, I understand. But if you're solving a problem then it might be quicker and easier (and cheaper) to buy than to build and blow something up. But as for your power source, that remains in serious question. Unless you only need a little more than an hour of performance.