Patent ID: 11936207
Assignee: CYPRESS SEMICONDUCTOR CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 10:
11. A power delivery system, comprising:
a transmitting coil; and
a Universal Serial Bus-Power Delivery (USB-PD) integrated circuit (IC) controller coupled to the transmitting coil, the USB-PD IC controller comprising a first comparator and a second comparator;
wherein the USB-PD IC controller is configured to:
detect a decaying coil voltage signal of a transmitting coil;
use a first comparator to trigger a cycle count of the decaying coil voltage signal, wherein the decaying coil voltage signal is an input signal of the first comparator;
when the first comparator triggers the cycle count, use a second comparator to count a number of cycles of the decaying coil voltage signal, wherein the decaying coil voltage signal is an input signal of the second comparator;
determine a quality factor (Q-factor) of the transmitting coil based on the number of cycles of the decaying coil voltage signal, a reference signal of the first comparator, and a reference signal of the second comparator; and
determine whether a foreign object is present based on the Q-factor and a foreign object detection (FOD) threshold level.