I am developing BQ76PL536 for 18 cell li-po charge. discharge, balance and protection purpose, compared to BQ77910A the main benefit of 536 is it easy to stack up without level shift communication path, however it is lack of msofet drive circuit like many other solution such as OZxxx or some other standalone T.I. battery management solution.
I have built a simple common drain N-channel mosfet circuit and use mosfet drive IC such as TC4426A to turn on and off the mosfet for charge and discharge paths, now i can control the discharge mosfet on / off without any problem, but on the charge mosfet, it is seem that the Vgs will increase together with whole circuit VCC increase that lead the charge mosfet turn on automatically, and i couldn't turn it off even i tie the gate of the charge mosfet to ground.
can anyone help ? i already spent 1 week on it :(