I would like to use SIM800L for M2M. I have power of 5V 2A for powering uC board and would like to add gsm module. It seems that SIM800L has rather strange voltage input rating: 3.4V – 4.4V.
What would be proper way to power it up with this configuration?
One proposal was to use zener diode with VF 1V, is this viable solution?
Best Answer
You could make a stable 4V from you 5V supply with voltage regulator, like TI's lm2596s. It has an adjustable output version which is capable of driving a max 3A load with excellent line and load regulation, beside providing the adjusted fix voltage (like 4V in your case).
I have used this IC with my GSM module which has similar supply voltage ranges like yours (3.4V - 4.6V, 4 recommended), it works fine.
Though, it requires more components and more space than a single zener diode, I think it is more reliable.
The datasheet has a good Design Component Selection Guide. Also, you can request samples if you have an educational or company e-mail address.