BQ25898: do not enter shipping mode but Closed Q4 fet

Kailun Liu

Expert 3393 points

Part Number: BQ25898

Hi team,

If the charger didn't enter shipping mode, could I closed Q4 FET?

over 2 years ago

0 Garrett Kreger over 2 years ago

TI__Mastermind 32280 points

Hi Kailun,

Yes Q4 BATFET can be closed due to a fault such as BATFET discharge over current protection. This behavior is described in section 9.2.2 of the datasheet. The thermal shutdown feature will also turn off the BATFET.

Best Regards,

Garrett

0 Kailun Liu over 2 years ago in reply to Garrett Kreger

TI__Expert 3393 points

Hi Garrett,

Thanks for your reply, what I want to check is could I turn off Q4 manually if didn't let BQ25898 enter shipping mode or trip protection?

0 Garrett Kreger over 2 years ago in reply to Kailun Liu

TI__Mastermind 32280 points

Hi Kailun,

The BATFET_DIS bit can be used to turn off Q4 FET manually at any time. Additionally when no input supply is plugged in driving QON pin low for approx. 15 sec briefly turns off Q4 FET. There should not be any other method to manually turn off Q4 BATFET.

Best Regards,

Garrett

0 Kailun Liu over 2 years ago in reply to Garrett Kreger

TI__Expert 3393 points

Thank you Garrett!

0 Kailun Liu over 2 years ago in reply to Garrett Kreger

TI__Expert 3393 points

Hi Garrett, could you please help to check this?

1. Could host send instruction to BQ25898 to turn off Q4 during adaptor plug in? (using VBUS to power system)

2. If the Q4 was turned off during adaptor plug in, how much current consumption in this time?

Thanks!

+1 Garrett Kreger over 2 years ago in reply to Kailun Liu

TI__Mastermind 32280 points

Hi Kailun,

1) Yes host can use BATFET_DIS bit to turn off Q4 and stop charging when adapter is plugged in. VBUS will continue to power SYS output.

2) When Q4 is turned off while the input adapter is plugged in current consumption from the battery is approx. 20uA.

Best Regards,

Garrett

Power management

Power management forum

BQ25898: do not enter shipping mode but Closed Q4 fet