Different phone receivers may support different charging power , like 15W, 7.5W, 5W, but how can 15W transmitter support the receivers? Charging power is controled by what kind of way, NCF3340 or receiver's reception capability?
Before the power transfer, there must be some phases approved before:
Ping: Transmitter executes a Digital Ping, and listens for a response.
Identification & control: Power Transmitter identifies the selected Power Receiver, and obtains configuration information such as the maximum amount of power that the Power Receiver intends to provide. The Power Transmitter uses this information to create a Power Transfer Contract.
These phases will check the compatibility between the transmitter and receiver, if these phases are complete and approved, then power transfer can start.
Throughout the power transfer phase, the Power Transmitter and Power Receiver control the amount of power that is transferred.
The Power Transmitter uses the Control Error Value and the actual Primary Cell current to determine a new Primary Cell current. After the system stabilizes from the communications of the Control Error Packet, the Power Transmitter has a short time window to control its actual Primary Cell current towards the new Primary Cell current. Within this window, the Power Transmitter reaches a new Operating Point: the amplitude, frequency, and duty cycle of the AC voltage that is applied to the Primary Cell. Subsequently, the Power Transmitter keeps its Operating Point fixed in order to enable the Power Receiver to communicate additional control and status information.
That is to say,
Ping is using FSK when transmitter executes a Digital Ping , a response from receiver is using ASK?
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