BQ25792: VBAT_PRESENT_STAT register update time

Hi Jeff-san

Thank you for answering.

If auto D+/D- detection is disable, What detection time is? 

Best regards,

Higa

Hi Jeff-san

Thank you for your support.

Just to be sure. Is this information about VBAT?
Could you please tell me where I can find the datasheet description to know that D+/D- detection is related to VBAT voltage detection?
My customers want that information.

Best  regards,

Higa

Hi Higa,

I apologize. I misread you original question as being about VBUS_PRESENT.   D+/D- is not related to BAT plug in.   When charge is enabled and no battery is installed, VBAT_PRESENT can be reported once V(BAT) rises above 2.5V.  We recommend that the host software use the ADC to read V(BAT), turn off charging, turn on BAT discharge current then reread V(BAT) from ADC in order to determine if a battery is present.  Alternatively, the host can monitor INT and if it sees rapid INT pulses caused by the BAT pin capacitors rapidly charging, terminating and recharging, then the host knows a battery is not present.

Regards,

Jeff

HI Jeff-san

I'll ask the original question again.

My customer would like to know the time from when VBAT>VBAT_UVLOZ is detected until the value of the VBAT_PRESENT_STAT register is updated.

Could you provide the information about it?

Best regards

Higa

Hi Higa,

As I mentioned above, there is no official battery detect circuitry for his device.  It simply reports battery present if the voltage on BAT/BATP goes above 2.5V, which will happen even if no battery is attached if charge is enabled.  So, we do not characterize the report time and do not recommend customers use that bit for determining if a battery is attached.

Regards,

Jeff

Hi Jeff-san.

I understood your advise.

But your advise isn't what I want.

You said : "It simply reports battery present if the voltage on BAT/BATP goes above 2.5V..."

What is the period until the reports battery present( VBAT_PRESENT_STAT="1") from when VBAT goes above 2.5V?

Best regards,

Higa