I’m designing an application board for my CM3, which will include a rechargeable li-ion battery.
Investigating the schematics I noticed transistor Q17, which isn’t typical for RK3566 applications. It essentially works as a diode from VBUS (voltage input) to VCC_SYS.
If I am correct, with typical USB 5V input, it will force VCC_SYS to be at least 4V, thus completely bypass RK817’s battery management, and charge low battery with uncontrollable current.
My question is, are my assumptions correct and if so, where is Q17 so I can remove it?
If not, why exactly it has been added?