Microchip Technology Incorporated
FOREIGN OBJECT DETECTION IN WIRELESS CHARGING SYSTEMS AND RELATED SYSTEMS, METHODS, AND DEVICES

Abstract:

Foreign object detection for wireless power transmitters and related systems, methods, and devices are disclosed. A controller for a wireless power transmitter includes a processing core and an analog to digital converter configured to sample at least one of a coil voltage potential and a coil current of a transmit coil. The processing core is configured to determine an expected reference Q-factor value responsive to the at least one of the sampled coil voltage potential and the sampled coil current, and compare the expected reference Q-factor value to a reference Q-factor value received from a wireless power receiver. The processing core is further configured to determine that a foreign object is detected proximate to the transmit coil responsive to a comparison of the expected Q-factor value to the reference Q-factor value received from the wireless power receiver.