BQ25703A: Charger doe not start up with 5V input and 0.5A ILIM setting

Arunthathi Chandrabose

Part Number: BQ25703A

With 2S setting, the charger output is expected to be 6.12V with no battery and no system load. But with the ILIM pin set to 0.5A, and charger input voltage at 5V, the output does not build up beyond 3V.

EVM also shows the same behavior.

over 6 years ago

0 Shishuo Zhao over 6 years ago

TI__Expert 3320 points

Hi There:

This is known bug for us. The specified voltage range for ILIM_HIZ is 1.0-4.0V. Between 1.00-1.15V, when no battery is attached, the converter cannot start up (load independent). It seems to happen around the input current switch point, which is from inductor current limit to ILIM limit. So the VSYS voltage oscillates around 2.8-3.2V, and remains there.

The application work around is adding 10nF capacitor from VDDA to ILIM_HIZ in order to initially set the pin to a higher voltage.

Regards

Shishuo

0 Arunthathi Chandrabose over 6 years ago in reply to Shishuo Zhao

Prodigy 20 points

The workaround is not helping. Behavior is still same.

0 Shishuo Zhao over 6 years ago in reply to Arunthathi Chandrabose

TI__Expert 3320 points

Please gradually increase the capacitance value to 10uF to see if it helps. Thanks.

Regards

Shishuo

0 Shishuo Zhao over 6 years ago in reply to Shishuo Zhao

TI__Expert 3320 points

Hi there,

We haven’t heard back from you. We are assuming you were able to resolve your issue. If not, just post a reply below or create a new thread if the thread has locked due to time-out.

Regards,

Power management

Power management forum

BQ25703A: Charger doe not start up with 5V input and 0.5A ILIM setting