Other Parts Discussed in Thread: TPS65987D
Tool/software:
looking for a simple solution to the following.
- I have an iPad and my device encased in a sealed housing.
- permanent USBC cable runs from iPad to my device to power my device
- a single USBC jack is exposed from the sealed unit which is only required to charge the iPad (no data connection required).
There are reasons to use an iPad instead of a battery pack that aren't relevant, but basically the iPad is acting as a battery that also needs to be recharged.
My problem is figuring out how to configure my device to allow the iPad to both source and sink power. I am not an USB expert and am really looking for a complete, simple, solution/example to copy. I would like it to be hardware configurable so that no i2c/programming/mcu is required.
I have tried a P-Channel MOSFET with a 5k1 resistor on the cc1 line, but I am struggling with dynamically sourcing/sinking from the iPad. The iPad doesn't switch to sinking as required.
Block diagram of the concept. My device requires 5v ~100ma from the iPad. Power can be cut off to my device (or not) while charging.