M66 module shut down suddenly

IoT Modules GSM Module
1

hi,

i have m66 module and renesas microcontroller. i can started module succesfully. Netligh is working. But after a while, module shut down suddenly. i checked the vbat voltage with oscilloscope, there isn’t any voltage drop to under 3.3 volt(this value is written in hardware design). i also checked pwrkey pin but i didn’t see any issues. İ didn’t send any command to module. İ just open the module with vbat and pwrkey pin.

2

When the GSM module is working in RF, there will be a large current, which will drag down the vbat and cause the module to restart. You can use the oscilloscope to monitor the vbat/VDD pin and observe whether there is a voltage drop.
In fact, we need additional capacitors to keep vbat stable, refer to our hardware design drawing