Wireless charging method and system for detecting foreign material during wireless charging

An apparatus for performing wireless charging transmission, the apparatus comprising:

• a transmission coil;
• a wireless charging transmission circuit;
• and
• a controller configured to:
• configure charging, based on an exchange of at least one predetermined packet with a detected wireless charging reception device,
• transmit power to the detected wireless charging reception device, based on the configured charging,
• temporarily stop transmitting power in response to receiving a foreign material detection request packet from the wireless charging reception device while the power is being transmitted, wherein the wireless charging reception device is configured to, before transmitting the foreign material detection request packet to the apparatus, adjust a load of supply power supplied to the power management module from the wireless charging reception circuit by lowering a current of the supply power supplied to the power management module from the wireless charging reception circuit,
• detect whether foreign material is present based on a resonance characteristic of the transmission coil while transmission of the power is temporarily stopped,
• completely stop transmitting the power in response to detecting that the foreign material is present, and
• reinitiate the transmission of the power in response to detecting that the foreign material is not present.

A method of performing wireless charging by an electronic device, the method comprising:

• receiving power from a wireless charging transmission device;
• determining whether a predetermined condition is satisfied while a battery is charging using the received power;
• and
• in response to determining that the predetermined condition is satisfied, adjusting a load of supply power supplied to the power management module from the wireless charging reception circuit by lowering a current of the supply power supplied to the power management module from the wireless charging reception circuit, and transmitting a foreign material detection request packet to the wireless charging transmission device.