SIM800L power supply

[Kris]

SIM800l problem with voltage. Modul SIM800L work with 3,4-4,4 VDC but M5 product give 4,9V. At this voltage the module does not connect to the network. To change it , I used MP2307DN step-down converter, but it is hard to set optimal voltage. I haved luck and set on 3,85V.

[felmue]

Hello @Kris

thank you for sharing your solution. With 5 V supplied from an external power supply I actually measure about 4.7 V going to the SIM800L due to the voltage drop of diode D1. But yes, that is still out of the specified VBAT absolute maximum rating of 4.5 V.

Thanks
Felix