Hi,i designed a custom Beaglebone Black Board and use TPS2051 or TPS2069 USB power switch.
USB Power comes from VDD_5V via MAX16909.

MAX16909 has supplied from 12V , 3.5A current limited DC power source.
I want to work with 3.3V Quectel EC25-EU mini PCIe module,so I used MIC29300-3.3WU-TR regulator to convert VDD_5V to 3.3V.

I have power issues with this system.When power up,MiniPCIe is working, but system restrarts or shutting down when Quectel starts cellular mode with peak current.

Could you help me about that problem ?

Schematics attached.

VBAT = 12V

 

Use a separate regulator fed by the 12 volt source to supply the power hungry cellular package, instead of letting it overload the 5 volt regulator. two regulators in series is not always a good choice, which is demonstrated for the TS very well.