BQ25606: Trying to pull 2A current from SYS without battery

Vahram Hambardzumyan

Part Number: BQ25606

Hello,

I'm trying to pull 2A current from SYS pin (the output of switching converter) and have no battery attached. I also disabled the charging with dedicated CE\ pin to be in safe side.

Do you have any idea why switching converter doesn't give at least 1A current from power path (voltage drops from 3.6V to 1.8V at 0.5A load, immediately)

I left the D+D- pins floating and supplied the IC from stable 5V source, so there is no input current protection, as input source qualification process passed successfully and unknown source should have been detected.

Is there possibility to supply my system using power path, which required 3.6V 1.5A power source, without battery, in general? Only input source present with 5V2A capabilities...

Schematic below:

Thanks,

over 3 years ago

0 Ning T over 3 years ago

TI__Guru 52301 points

Hi,

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.

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 the d/s, the IINDPM is set to 200mA if VSYS is less than 2.2V.

Do not apply more than 200mA load at VSYS when VSYS<2.2V.

Thanks,

Ning.

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BQ25606: Trying to pull 2A current from SYS without battery