BQ25306: The charge current exceeds the set value through the ICHG pin

Lumina Gui

Part Number: BQ25306

Hi TI Teams,

We set the charge current of BQ25306 to 1A(2-cell Li-lon battery), but the actual measured charging current can reach 4A when the battery voltage is low, which have exceed the maximum charging current supported by BQ25306 (3A).

The schematic is show as below:

The input voltage is 9.5V and the battery is 2-cell Li-lon. The output current waveform of SW pin is as follows:

1) With the load

2) Without the load

Can you help to analyze the cause of this problem?

Thanks,

Kind Regards

over 1 year ago

0 Ning T over 1 year ago

TI__Mastermind 48691 points

Hi,

1. For "With the load", does it mean the battery is connected to the BAT pin?

2. For "Without the load", does it mean the BAT pin is floating?

3. Is there any load other than the battery connected to the BAT pin?

4. Is the scope waveform for the SW pin voltage?

Thanks,

Ning.

0 Lumina Gui over 1 year ago in reply to Ning T

Expert 2805 points

Hi Ning,

Thanks a lot. We have found the reason for this problem. The high voltage during the test caused the MOSFET which connected to the BAT output to be broken downone, which result this problem.

Thanks,

Kind Regards

0 Ning T over 1 year ago in reply to Lumina Gui

TI__Mastermind 48691 points

Hi,

Great! Thanks for the update!

Regards,

Ning.

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BQ25306: The charge current exceeds the set value through the ICHG pin