BQ25606: USB charging current limits

Hermetica

Part Number: BQ25606

Dear TI team,

we are considering to use the part BQ25606 on a PCB that is designed to charge Li-ion batteries via USB both from computers and wall adapters. The charger IC automatically detects via the D+ / D- singals which kind of wall adapter is connected or if a computer is connected and limits the charging current accordingly.

I wonder why the case of USB100 (a limit of 100 mA) is missing. Some USB ports from old computers may only be able to supply 100 mA. Wouldn't it pose a risk using this charger IC if one would connect it to a USB port than can only supply 100 mA?

All the best,
Frederic.

over 4 years ago

0 Ning T over 4 years ago

TI__Guru 57611 points

Frederic,

We are checking and will get back to you.

Thanks,

Ning

0 Ning T over 4 years ago in reply to Ning T

TI__Guru 57611 points

Frederic,

If the charger is powered up without the battery, VSYS will start from 0V and may stuck in 200mA IINDPM if SYS tries to pull too much current during the start-up. Referring to Iin_start spec on page 9 of the d/s, the IINDPM is set to 200mA typically if VSYS is less than 2.2V typically.

Please visit https://e2e.ti.com/support/power-management/f/196/t/890626 for BQ25606: Schematic Review and PCB Layout Design Tips. Additional Information including FAQs is available http://www.ti.com/lit/an/slva924/slva924.pdf Designing A Standalone Single Cell 3-A Charger with the bq25606.

Thanks,

Ning.

Power management

Power management forum

BQ25606: USB charging current limits