BQ25890H: system will reboot without battery

below information is the register value of bq25890H charging IC on our product.

Here is the schematic 

AS330_A_20210831.pdf

PCB plug in USB cable

RT181 BQ25890H Charger Out --> 2.4V

PCB power on with Battery

RT181 BQ25890H Charger Out --> 3.965V

Len Hsu

Hi Ning,

There are some questions that the customer wants to double confirm.

1. So BQ25890H doesn't need any firmware for working? Or the firmware was burned when it  sell? (so the customer just need to setup the reg value?)

2. As the datasheet mentions, at reg14, that can save the reg value even the system reboot. Does that mean there is a ROM that can record the value?

3. Is there any way that can set the default reg value at the factory?

4. As we know we can set reg14 for default setting when we reboot the system, is there any possible way that will make BQ25890H reg setting back to default setting?

5. The datasheet mentions that at this condition IC will start Power-On-Reset process, and will make the reg setting back to default.

And now they remove the USB power and plug again, it will start POR process too, is there any way to avoid the IC back to default setting? or work around the POR process? or save the reg setting that was set?

Best Regards,

Len Hsu 

Hi Ning,

Thanks for your reply.

So there there is a memory(like ROM) inside BQ25890H for record the default setting, right?

Best Regards,

Len

Hi Ning,

The customer that still have some questions that wants to confirm.

Here is the reg setting now.

1. Is there any way to know how much Isys is? If it's yes, how?

2. For now charger current can be 1.65A after the reg setting, but as the datasheet mentions, is can be 3A.

Does there any setting needs to be changed?

3. As BQ25890H datasheet figure 11, Isys and Ichg are rising and falling by linear, does that means if we are not using battery power (not enter Supplement Mode) , it should be Isys_max = Ichg + Isys?

Thanks for your help!

Len