VVD_Ext voltage is not stable in MC60 module

IoT Modules GSM Module
1

Dear Quectel Team,
We have develop the telematics board with MC60 module, during testing, I have observed the VDD_Ext (Pin 5) voltage is not stable. For your reference, please find an attached image where the Yellow line represents the PWR Key signal, and the Blue line represents VDD_Ext.

Here’s a brief overview of the observed behavior:

  • The PWR Key voltage is initiated with the GSM_Supply (4V).
  • After 200ms, we pull down the PWR_Key.
  • Approximately 80ms later, VDD_Ext voltage is established (2.82V) for 1.48 seconds before dropping.

I have already verified the power supply and the sequence of power-on, and they appear to be in order. However, the instability in VDD_Ext is a concern.

Could you please share your view on this issue, Additionally, if there are specific tests or steps you recommend to further diagnose the problem, please let me know.

VDD_EXT Down issue in MC60
VDD_EXT Down issue in MC601600×1200 212 KB

2

Hi
Do you mean the instability of VDD_EXT when working? This should be normal, 2g module in the RF operation, there will be a large current, which will drag down the VDD voltage value