The TI's battery management IC BQ2403x have the chip enable signal which needs to pull up when working. There are four potential power sources to enable this CE signal which are: AC, USB, BAT and System(LDO or OUT) power. However, I think none of them is proper(Maybe I haven't understood this signal correctly).
- AC or USB or BAT power
None of the three ports must be present when working, user may just use battery or usb or other, so either can be used to power the CE signal alone.
- System Power
Before the CE is enabled, the system will not get any power, so it can't power the CE signal.
The idea I can have now is to connect AC/USB/BAT power with 'OR' gate to power the CE but I feel it's kind of complicated.Is there any simple way to power the CE signal?