Dear all,
after implementing a BQ77910 circuit and going through all the chalenges in using the series topology, I discovered exteremly high quiescent currents.
my schematic is attached.
clearly I can see 2 areas to take care of:
- DSG pin with a voltage devider of 200K and 200K (R41 & R48). this discharges ~17.5 us and I can maybe live with it.
- CHGST pin has a terrible voltage divider of 15K and 1K (R34 & R33) which kills the batteries... it is ~2mA.
do you see any more points of leekage?
my solution is to increase the resistors of CHGST to 750K and 50K.
do you think it is too noisy for this pin?
can you think of a more steady power source to feed CHGST more than 0.9V it needs, other than P+?
do you think maybe connecting Vbat pin (pin 31) directly to CHGST or through a resistor will work?
any suggestion will be welcomed.
best regards,