I'm going through this application note - because it is said that the MCP73833 device does not allow to charge the battery and drive the load simultaneously.
Hence, they've given the below circuit in the above application note. I'm having trouble finding understanding the working of the protection circuit marked, which allows the input voltage to disconnect the load from the battery while simultaneously driving the load itself.
Can someone explain how the protection circuit works?
Pg.10 of the application note mentions that when power is supplied, it will charge the battery and the load will be supported by the power source as well.
When a power source is present, the gate of the P-Channel MOSFET Q1 is pulled high which turns Q1 off disconnecting the battery from the load while the source also supports the load through D1. MCP73833 charges the battery through VBAT at the same time.
When a power source is not present, the gate is pulled down through the resistor Rpull which turns Q1 on and the battery supplies power to the load through Q1.
