HL7648 bricked due to power sag?

Normally I have the current limit set to 1.5A. I disconnected the HL7648 setup and set the power supply limit to 100 mA to charge a single LIPO cell. Then I connected the HL7648 but forgot to raise the current limit. The PWR_ON_N pin is pulled low to boot it. The HL7648 current draw jumps to about 50 mA and never changes. The AT interface doesn’t work and the UART1 CTS stays high.

I think I must have bricked the HL7648 due to the 100mA current limit. This also means the module might be bricked if powered up on a dead battery. Is there any recovery? The reason I ask here is the only way I know how to get a replacement module is through DigiKey and presently their shipping delay is about a week due to Covid restrictions.

Hi @sales ,

It means that you can get the AT com port but it doesn’t work or there are no com ports that appear. How many the electric potential energy value of the module at that moment?
Any in the life of the module after powering on?

Before this, the current fluctuated up to 200 mA while it connected to the network. Now it draws 50mA constant when the PWR_ON_N pin set low.

Once the power on pin is set low, the module 1.8V output appears. If the the reset pin set low, it will return to low power. There are no other signs of life.

The module is powered by 4.1V

Hi @sales ,
Sorry for the late response.

I cannot help if it is hardware issue. You should contact your distributor to get further support

The module has been replaced with a new one and it works. I have tested the power supply to see if there is voltage overshoot during pulsed current limited over loads. It seems well behaved. Just for the record seems the module simply died as a result of the power supply current limiting. I do not know how I can hold the distributor responsible.