Avago Technologies International Sales Pte. Limited

Jim Le

John S Walley

Marc Keppler

Shiju Wang

Chongming M Qiao

Mark David Rutherford

Ashfaqur Rahman

A wireless power transfer device may include a circuit couplable with a coil to transmit or receive a first signal providing wireless power through the coil. The first signal may be modulated with second signals. A packet within any of the second signals may include first bits associated with a preamble and second bits associated with data. The device may further include a controller to measure temporal variations of at least one of the first signal, a rectified version of the first signal, or the one or more second signals. The controller may further determine thresholds for distinguishing between bits in the packet based on the temporal variations. The device may further demodulate the signals using the one or more thresholds to identify the preamble of the packet and extract the second bits associated with data from the packet when the preamble of the packet is identified.

Wireless power transfer with in-band preamble monitoring and control

The subject technology is directed to power conversion systems and methods. In some embodiments, the subject technology provides a device comprising a first switch configured to receive a first signal and a second switch configured to receive a second signal. A voltage generator is coupled to the first switch. The device further comprises a first resistor coupled to the first switch and a second resistor coupled to the first resistor. The first switch is further coupled to a first capacitor, which acts as a charge pump to generate the negative voltage such that the output of the device comprises both positive and negative voltages. Embodiments of the subject technology achieve bipolar signaling based on a unipolar design, effectively minimizing DC leakage and overall power consumption. There are other embodiments as well.

Leakage reduction for rectifiers and inverters using bipolar signaling

A rectifier includes digital timers to control FET switching rather than direct measurement of current and/or voltage. The digital timers control turn-off time to compensate for a delay produced by comparators in the rectifier. The digital timers are adjusted over multiple cycles to arrive at a turn-off time that produces zero current turn-off. The digital timers may be periodically or continuously readjusted based on a preceding set of cycles. Adaptive turn-off via digital timers is useful for discontinuous conduction mode suppression.

Rectifier control with adaptive turn-off

A system and method for monitoring signal quality metrics coupled with closed-loop control improves rectifier signal quality and stability. The closed-loop control passes the metric through a high-pass filter and captures error values. This signal is then passed to a controller to adjust rectifier settings. The measured signal, where signal quality is derived could be V, F, network coil measurements, is used for ASK demodulation, or the like. The controller identifies noise levels and noise types in real-time, and sets parameters of the rectifier to preserve system stability. The controller may set baud rates and preamble thresholds in a wireless power transfer system in response to identified noise levels and types.

Rectifier stability enhancement using closed loop control

A system is disclosed. The system includes a first circuit that includes a first receiver configured to receive a wireless power input, a first conductor, and operably coupled to the first receiver, and a switch network operably coupled to the first conductor configured to rectify the wireless power input and generate a rectified voltage. The first circuit further includes a first field effect transistor operably coupled to the first conductor and configured to receive a portion of the wireless power input from the first conductor and output an output voltage back to the first conductor based upon a gate input. In one or more embodiments, the first circuit further includes a first controller configured to determine if the rectified voltage is greater than a voltage threshold and transmit a transmission of the gate input to the first field effect transistor if the rectified voltage is above the voltage threshold

Rectifier buck with external FET

A rectifier modulates a signal in a rectifier by turning on a low side field effect transistor to produce a load at a coil network in response to a low side field effect transistor in an alternative diagonal being on. The system measures signal quality to determine a necessary modulation depth for ASK communication; then determines a switching time and magnitude of a ballast signal to apply to the low side field effect transistor to achieve that modulation depth.

Rectifier fast load ballast

A wireless power transfer device may include a first circuit configured to be connected in series with a coil, a second circuit, and a switch, where switching a state of the switch may selectively couple the second circuit to the first circuit. The switch may be driven by a pulse width modulation (PWM) signal. The device may further include a PWM controller to receive measurements indicative of wireless power transferred through the coil, generate the PWM signal, and adjust the PWM signal to provide the wireless power transferred through the coil according to a selected metric.

Impedance matching for wireless power transfer

A system is disclosed. The system includes a first circuit that includes a first receiver configured to receive a wireless power input, a first conductor, and operably coupled to the first receiver, and a switch network operably coupled to the first conductor configured to rectify the wireless power input and generate a rectified voltage. The first circuit further includes a first field effect transistor operably coupled to the first conductor and configured to receive a portion of the wireless power input from the first conductor and output an output voltage back to the first conductor based upon a gate input. In one or more embodiments, the first circuit further includes a first controller configured to determine if the rectified voltage is greater than a voltage threshold and transmit a transmission of the gate input to the first field effect transistor if the rectified voltage is above the voltage threshold.

Rectifier buck with external fet

A system for rectifying power is disclosed. The system includes a switch network that includes a plurality of switches configured to receive wireless power input and generate a rectified voltage. The system further includes a first conductor coupled to the first receiver and the switch network configured to transmit a first alternating current to the switch network. The system further includes a second conductor electrically coupled to the first receiver and the switch network, configured to transmit a second alternating current having a second voltage to the first receiver. The system further includes a controller configured to determine a rectified voltage signal and to transmit an input to at least one switch of the plurality of switches based on the rectified voltage signal to change an ON/OFF state of the at least one switch of the plurality of switches, modifying the voltage.

Rectifier dynamic boost

Impedance matching for wirelss power transfer

A dual-comparator rectifier circuit of a wireless power receiver includes a receive coil configured to generate a current in response to receiving power through electromagnetic waves from a wireless power transmitter and a bridge circuit. The bridge circuit includes four branches, and one node of each of the four branches is coupled to one of a first node or a second node of the receive coil. A first branch and a second branch of the four branches are coupled to the first node and the second node of the receive coil and include a first circuit and a second circuit, respectively. The first circuit includes a first comparator and a first switch circuit and the second circuit includes a second comparator and a second switch circuit. The first circuit and the second circuit can set a dynamic turn-on threshold for the first switch circuit and the second switch circuit, respectively.

Growing community of inventors

Fort Collins, CO, United States of America

Jim Le