Abstract: Embodiments described herein provide a wireless power transmitter that dynamically adjusts the deadtime to reduce power loss. Specifically, the wireless power transmitter includes a transistor circuit for switching a first voltage at a first node and a second voltage at a second node, and a LC circuit coupled between the first node and the second node. The wireless power transmitter further includes a controller coupled to the transistor circuit. The controller is configured to determine whether either of the first voltage and the second voltage is negative during a deadtime of switching. The controller is configured to increment or decrement the deadtime by an adjustment amount depending on whether negative voltage is detected.

Abstract: Embodiments herein provide a device for calibrating a voltage driven by a PWM signal for a circuit board. The device includes a controller configured to generate the PWM signal according to a PWM duty cycle value, and a voltage regulator configured to generate an output voltage according to the PWM signal. The controller is further configured to calibrate a relationship between the PWM duty cycle value and the output voltage based on a plurality of configured PWM duty cycle values and a plurality of corresponding voltages measured from the voltage regulator, and drive the circuit board by configuring the PWM duty cycle value based on the calibrated relationship.

Abstract: According to some embodiments, a phone having a metal detector function is presented. In some embodiments, the phone includes a transmit coil and a microcontroller coupled to drive the transmit coil, the microcontroller monitoring a current or a voltage on the transmit coil and indicating the presence of a metal object.

Abstract: A wireless power system includes a receiver. The receiver may include a rectifier coupled to a receiver coil to receive power. The receiver may include a detector coupled to the rectifier to receive a monitor signal from the rectifier. The detector may provide a range signal indicating whether the monitor signal is outside a predetermined range. The receiver further includes an oscillation determiner coupled to the detector to receive the range signal. The oscillation determiner may determine that the rectifier is in an oscillation mode or is not in an oscillation mode. In some embodiments a communication unit is coupled to the oscillation determiner. The oscillation determiner may communicate a power adjustment signal and may request increased power through the communication unit.

Abstract: In a wireless power transfer operation, the operating parameters are adjusted to improve efficiency by reducing the transmit and receive coil currents as follows. First, the transmitter causes the receiver to reduce the receive coil current to the lowest value based on the transmitter/receiver communication while still delivering the same amount of power to the load as before the AC current was adjusted to the minimum value. Then the transmitter may change the operating parameters to increase or preserve the power provided to the receiver without decreasing efficiency or with only small decrease in efficiency, or with increasing the efficiency. For example, the transmitter may increase the VBRG voltage (the DC voltage powering the transmit coil) or the operating frequency to maintain or increase output power levels at lower or the same AC and DC current levels. Other features are also provided.

Abstract: A wireless power transmitter and a receiver device can communicate through a bi-directional communications channel that uses the wireless power signal transmitted from the transmitter to the receiver.

Abstract: In accordance with some embodiments of the present invention, a method of determining a Q-factor in a transmit circuit with a resonant circuit includes setting a system voltage; performing a coarse scan to determine a course resonant frequency; performing a fine scan based on the course scan to determine a resonant frequency; performing a final measurement at the resonant frequency to determine an average system voltage and an average peak voltage of the resonant circuit; calculating a Q parameter from the average system voltage and the average peak voltage; and calculating the Q-factor from the Q parameter.

Abstract: A wireless power system includes a receiver. The receiver may include a rectifier coupled to a receiver coil to receive power. The receiver may include a detector coupled to the rectifier to receive a monitor signal from the rectifier. The detector may provide a range signal indicating whether the monitor signal is outside a predetermined range. The receiver further includes an oscillation determiner coupled to the detector to receive the range signal. The oscillation determiner may determine that the rectifier is in an oscillation mode or is not in an oscillation mode. In some embodiments a communication unit is coupled to the oscillation determiner. The oscillation determiner may communicate a power adjustment signal and may request increased power through the communication unit.