I'm creating a new project that requires a LiPo to be charged from USB, the circuit can then be powered from either the LiPo, USB or an external Voltage (don't know which will be available at any given time). Charging should however only be done from USB. My setup at the moment uses Schottky diodes to switch between these sources leading to the voltage regulator. The system uses fairly little current but the diodes will still have a voltage drop associated which I would like to minimize. (Zeners on the schematic should be schottky diodes, Kicad doesn't seem to have the symbol)
I'd appreciate some critique and suggestions about this configuration and any ideas would be appreciated.