BQ25010 Behavior of the DC/DC output when to remove the battery .

Rene Souza Lima

Other Parts Discussed in Thread: BQ25010, BQ24072

Hi,

I am using bq25010 to charge my battery 900mA, but when removing the battery and using on AC power, DC/DC output fell from 3V3 to 0.7V sometime later . It is normal? It is possible to maintain the DC/DC output to 3V3 ?

Thank you and I very much appreciate all of your feedback!

over 9 years ago

0 Jing Zou over 9 years ago

TI__Mastermind 20570 points

What is the current limit on your AC power supply? How much current does the load consumes on the DC/DC output?

0 Jing Zou over 9 years ago in reply to Jing Zou

TI__Mastermind 20570 points

If at start up the battery is not presented, then no output is on pin 16 (BAT/OUT) thus no input for the DC/DC converter.

0 Rene Souza Lima over 9 years ago in reply to Jing Zou

Prodigy 30 points

The AC power supply is limited up to 2A . The load consumes up to 60mA.

0 Rene Souza Lima over 9 years ago in reply to Jing Zou

Prodigy 30 points

This situation happens in operation. About 2 or 3 hours after removing the battery
the output DC/DC fell from 3V3 to 0.7V. Is it normal operation?

0 Jing Zou over 9 years ago in reply to Rene Souza Lima

TI__Mastermind 20570 points

The bq25010 buck is powered from the battery. After battery removal, do you see the buck converter still switching? My suspicion is the buck enters the low power mode and slowly discharges the output capacitor. If you would like your system to maintain power on after battery removal, then I would suggest to use a charger with power path such as the bq24072/3/4/5/9.

0 Rene Lima over 8 years ago in reply to Jing Zou

Prodigy 70 points

Below there are picture before and after removal the battery.

Power management

Power management forum

BQ25010 Behavior of the DC/DC output when to remove the battery .