I am using the BQ24075 battery charger IC (datasheet here). If I am reading the datasheet correctly, on page 6 it says that the absolute maximum sink current for the CHG output pin is 15mA. I require this pin to sink at least 40mA so I assume I will need to use a P-channel MOSFET whose gate is controlled by the CHG pin.
The circuit I am considering resembles the following:
When the device is not charging, I expect CHG to be high impedance. When the device is charging, CHG will be pulled to GND which will switch the MOSFET on and allow current to flow into the load. Please ignore the load resistor, I have placed it there only for visual reference.
From reading other posts that concern the gate resistor, it appears as though having a large (>100Ω) resistor may cause a significant delay switching the MOSFET on. I am not too concerned with the delay, but are there other concerns with using this resistor? Could I increase the value so that less current is used when the CHG pin is pulled to GND? Finally, would this circuit work correctly as I have described it?