BQ25730: Does input current include system current?

Jeffrey Blum

Part Number: BQ25730

Tool/software:

I'm working on a board that's intended to be a scaled-up version of a product I've already designed. Unfortunately, the scaled-up version has a lot more peripherals and a more powerful CPU, so it requires 17A max as opposed to just 10A to run the system and charge the battery simultaneously. The battery specifications are the exact same. Can I keep using the BQ25730 in this case? Or do I need to find one with an input current limit above the combined current draw of the charger and the system?

10 days ago

+1 Tiger Zhou 10 days ago

TI__Mastermind 24865 points

HI, Jeffrey,

You can continue to use BQ25730. Just change the RAC current sense to scale up the current. See below explanation.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1253903/faq-bq24800-i-am-using-sense-resistor-values-other-than-10m-to-extend-the-input-current-range-but-the-gui-does-not-display-this-extended-range

Regards,

Tiger

0 Jeffrey Blum 9 days ago in reply to Tiger Zhou

Prodigy 80 points

I want to make sure I'm understanding this correctly. The BQ25730 supports a current limit up to 10A with a 5 milliohm resistor. If I change the resistor to 3 milliohms, then the current limit jumps to 16.67A. Also, when reading current values, I need to multiply the value by 1.67 to get the actual current. Does that make sense?

0 Tiger Zhou 9 days ago in reply to Jeffrey Blum

TI__Mastermind 24865 points

You got the idea.

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

Power management

Power management forum

BQ25730: Does input current include system current?