Engineer's Asylum

Choose the right voltage regulators


Hi everyone. I’m designed a PCB for 4 dc motor. In this PCB there are 2 tb6612fng circuits controlled by esp8266. My problem is that I can’t find the right regulator for this board. I planned to use 3 18650 battery. How can I use these batteries with the right regulator? The board needs a 5v supply with at least 4 amperes.
Thanks for answers.


Hi, Welcome to our forum,

Are are trying to just regulate three 18650 battery connected in series? or Are you trying to protect three series 18650 batteries so that you charge and discharge it without damage?


I can charge them separately. My main problem is regulation. But if you have a solution for both of them that would be better.



You may use a DC-DC buck converter to do the job. A series arrangement of these 18650 batteries will add the voltage 11.1V. Use an LT3742 buck converter to step down the voltage to 5V with 4A output current. No need of any linear regulator, the buck converter will do the job. But I don’t know how long the power will last which entirely depends on the capacity of Li-Po cells you have.