BQ24392: power off

CHG_DET  is output pin, the IO connected to CHG_DET is not  input pin?

Best

Brian

Hi Brian,

BQ24392 is connected to the system microcontroller via DI, and the microcontroller side has a 100kΩ pull-up at the system power supply of 3.3V like the thread below.

https://e2e.ti.com/support/switches-multiplexers-group/switches-multiplexers/f/switches-multiplexers-forum/475057/bq24392-chg_det-output/1709344?tisearch=e2e-sitesearch&keymatch=BQ24392%25252520CHG_DET%25252520diode

Because of the diode, they see 0.6V on the CHG_DET pin.

Regards,

Shoo

Hi Brian,

In addition to the above question, When the BQ24392 is powered off, will it be a problem if a voltage of about 3.3V is applied to the DP_HOST pin because High in DP for USB host to support Fullspeed ?

If there are the problems, Let me know any solutions.

Regards,

Shoo

Hi Shoo:

   0.6v on CHG_DET pin should be ok, but 3.3v on DP_HOST  could back drive to  supply pin and if it lasted for sometime, it may cause liability issue.

Best

Brian

Hi Brian,

3.3v on DP_HOST is applied in 30ms as attached waveform.

If it might cause the issue, Could you give us the solution to prevent from applying 3.3V  to DP_HOST?

Regards,

Shoo

Hi Brian,

The following pins are applied 3.3V always when the BQ24392 is powered off(VBUS off).

Is that fine?

・SW_OPEN pin

・CHG_AL_N pin

・GOOD_BAT pin

Regards,

Shoo

Hi Shoo:

  If 3.3V is always on on those pins, it could back drive to supply pin and could cause reliability issue.

Best

Brian

Hi Brian,

 How to avoid it?

Regards,

Shoo