Hello dear Texas Instruments engineers!
I develop power system for portable computer, and I use BQ24735 for battery charger.
I made a disign like DVK for bq24735. So, when I supply my system from external power supply - system is work. Switching between external power supply nand battery is work fine to.
My problem:
When I disconected battery, and try to change charge voltage and charge current over SMBus, the bq24735 turn off external power supply. If after this case i connect battery, so my system can work.
So it is mean when I try to increase charge voltage and current ACFET is closed and BATFET is opend.
What can be connected such an anomaly? I checked my host system - it is worK fine. After setting options over SMbus I can read it, and I can see that their values are correct.
So when I increased charge voltage above then 3072 V with charge current (for examle) 521 mA, bq24735 turn off external power supply and open BATFET. And if I connect battery my systen will work.
For out from this state I need disconnect external power supply, whait at least 30 sec, and start up my system again.
There are no any short circuitS in my PCB design. I checked it very carefully. And system can work from battery, when bq24735 is in this unusual condition!
Has anyone had similar problems?