USB Type-C – Power Negotiation Issues
Hello this is my first thread here.
At this time I am developing a Proof of Concept (POC) that is an adapter for Type-C devices..
I need direction on which PARTS: connectors and resisters I would need to complete the build.
I am taking a preexisting device that uses a designated 3.7V 550mAH LIon battery for power.
I want to cut the wires and create an adapter, so I can use alternative power sources via USB Type-C connectors.
The first Goal is that the adapter will receive power from a Samsung S8 mobile device.
Device Specs:
10W to power 1.3 R.
3.7V and 550 mAH LIon battery existing power source; to be removed.
The device should receive 3.5V to 3.8V range and can not receive more than 4V.
I am unsure of the Battery Discharge /Pulse Amp rating? But I am working on it.
1) Can an USB-C connector control a variable Voltage under 5V or is it only preset voltages 3V or 5V?
I read the paper that mentioned 3V and 5V, with max of 15W=5V x 3A, before having to switch to PD, but it didn't elaborate on if something like 3.6V is possible from the Host.
I guess, If the phone sends 5V I could put the correct resistor in there to step it down if needed.
2) Which correct Type-C connector, Part ,chip resister do I need to negotiate with the phone or any other Type-C device to deliver 10W?
I am unsure at this time what the Discharge/Pulse Amps are for a Samsung S8 Lion poly phone battery or any other for that manner.
I have heard that it has provided 7.5W to power a peripheral device, but that was all that was demanded. don;t know if that's a max or not.
If I have to put an inductor, booster, or capacitor in the adapter I guess I will.
3) Is 10 Watts, 10 Watts no matter how you slice it? e.g 5V x 2A=!0W or 3.5V x 2.69A=10W.
Just wondering if it would fry the circuit?
That's it for now, I appreciate any help I can get.
Getting the correct chip connector setup is critical. Thanks.