For a Li-Ion battery charger, I chose the TI BQ24040, datasheet attached. The watch is going to have charge contacts that go to the outside world and connect to the input voltage pin of the BQ24040 and ground. What happens when there’s a battery connected to the charger output, and Vin is shorted to ground? Is there a chance that the battery could back power through the device, to the Vin pin, to ground? We’re planning to use a series Schottky diode on the input to protect against reverse polarity, so maybe this would be enough to protect against input shorts? There’s some logic on the pass transistor that limits current output if the input voltage is below a threshold (to protect the charging source), so maybe this would also prevent current flow if the input is shorted?
Any help appreciated
Calum
