Apple Inc.

Advanced Micro Devices Corporation

Bharat K Patel

Abby Cherian

Chanwit Prasantanakorn

Manisha P Pandya

Inhwan Oh

Antoin J Russell

Zaki Moussaoui

Paul J Costa

Liang Chen

Yantao Song

Arunim Kumar

Neal V Cecil

Ruenjou Lu

Zachary Strachan Harris

Timur O Starobinets

Andrew Gray

Dane Oleson

Fei Ni

Steve Xing-Fu Zhou

Edward H Frank

Weihong Qiu

Kevin Scott Fetterman

Michelle Rae Goldberg

Saining Ren

Kathleen A Bergeron

Asif Iqbal

Mark K Sin

Paul S Michelsen

Rohan Dayal

Adrian E Sun

Stuart A Taylor

David R Cox

Kisun Lee

Nicholas W Ruhter

Xiaoyang Zhang

Ron Rafer Floresca

Jerald Polestico Guillermo

Steven Ichung Kuo

Chad O Simpson

John Douglas Field

Victor M Ma

Erik A Gutfeldt

Derrick C Lau

Steve X Zhou

Harsha Lakshmanan

Deborah Claire Sharrah

Malhar V Bhatt

Kim Phuong T Truong

Lee M Schaff

A power converter can include a switching bridge having two input terminals that receive an input voltage and a switch node coupled to a primary winding of a transformer; at least one rectifier device coupled between a secondary winding of the transformer and an output of the power converter; and a common mode noise compensation capacitor. A first terminal of the common mode noise compensation capacitor can be coupled to a connection between the secondary winding of the transformer and the at least one rectifier device, and a second terminal of the common mode noise compensation capacitor can be coupled to one of the two input terminals. The common mode noise compensation capacitor can be coupled to an energized or a grounded input terminal. The common mode noise compensation capacitance can be selected to be equal to the turns ratio of the transformer times the parasitic capacitance of the transformer.

Common mode noise cancellation for LLC resonant converters

A power factor correction circuit can include an input that receives a rectified AC input voltage; at least one switching device operable to control an input current of the power factor correction circuit to be in phase with the rectified AC input voltage; and control circuitry that controls the at least one switching device to produce a clipped sinusoidal input current, thereby increasing peak load capacity of the power factor correction circuit. The control circuitry can operate the at least one switching device in a critical conduction mode. The power factor correction circuit can further include an inductor having an inductor current therethrough controlled by the at least one switching device and the control circuitry. The inductor can be sized for a peak current corresponding to a peak of the clipped sinusoidal input current.

PFC design technique for high peak load

A power converter can include a rectifier that receives an AC input voltage and produces a rectified output voltage, a power factor correction (PFC) converter having an input coupled that receives the rectified output voltage of the rectifier and an output that provides an intermediate DC bus voltage, a DC-DC converter having an input that receives the intermediate DC bus voltage and produces a regulated DC output voltage, and control circuitry for the PFC converter stage that includes a relatively slower control loop that controls the PFC converter during steady state load conditions and at least one relatively faster control loop that controls the PFC converter during transient load conditions.

Power supply with active power buffer

A power converter can include a DC-DC converter having an output with an active power buffer coupled thereto. The active power buffer can include an energy storage capacitor and one or more switching devices selectively coupling the capacitor to the output to alternately store energy in and discharge energy from the capacitor. Control circuitry can include a DC-DC converter control loop that operates the DC-DC converter to regulate an average voltage across the capacitor and an active power buffer control loop that operates the one or more switching devices of the active power buffer to regulate an output voltage of the power converter. The DC-DC converter control loop can include a relatively slower control loop that controls the DC-DC converter during steady state load conditions and at least one relatively faster control loop that controls the DC-DC converter during transient load conditions.

A power converter can include a DC-DC converter stage having an input coupled to an input of the power converter and an output coupled to an output of the converter and an active power buffer coupled to the output of the power converter. The active power buffer can further include an energy storage capacitor and one or more switching devices selectively coupling the energy storage capacitor to the output of the power converter so as to alternately store energy in and discharge energy from the energy storage capacitor. Control circuitry of the power converter can include a first control loop that operates the DC-DC converter stage to regulate an average voltage across the energy storage capacitor of the active power buffer and a second control loop that operates the one or more switching devices of the active power buffer to regulate an output voltage of the power converter.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

Power supply with current limit on individual conductors

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using an output circuit that includes a wireless power transmitting coil. Measurement circuitry is coupled to the output circuit to help determine whether the wireless power receiving device is present and ready to accept transmission of wireless power. The measurement circuitry includes a measurement circuit that is coupled to the output circuit and that measures signals while oscillator circuitry supplies the output circuit with signals at a probe frequency. The measurement circuitry also includes a measurement circuit that is coupled to the output circuit and that measures signals while the oscillator circuitry sweeps signals applied to the output circuit between a first frequency and a second frequency to detect sensitive devices such as radio-frequency identification devices. Impulse response circuitry in the measurement circuitry is used to make inductance and Q factor measurements.

Wireless charging system with object detection

A power converter can be implemented as a series of power conversion stages, including a wireless power conversion stage. In typical embodiments, the power converter receives power directly from mains voltage and outputs power to a battery within an electronic device. A transmitter side of the power converter converts alternating current received from a power source (e.g., mains voltage) to an alternating current suitable for applying to a primary coil of the wireless power conversion stage of the power converter.

Low-profile power converter

A power converter can include an input boost converter stage having an input configured to receive a rectified AC input voltage and an output configured to deliver a DC bus voltage and a second switching converter stage having an input configured to receive the DC bus voltage and an output configured to deliver a regulated output voltage. The input boost converter may be configured to be operated in a flat current mode to maintain a substantially constant DC bus voltage over a broad range of AC input voltages. The input boost converter may be further configured to be operated in an active blanking mode, wherein operation of the boost converter is prevented during a controlled blanking interval of each cycle of the rectified AC input voltage. The controlled blanking interval may be increased responsive at least in part to an increase in the AC input voltage and/or may be decreased responsive at least in part to a decrease in the AC input voltage.

AC-DC converter with boost front end having flat current and active blanking control

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using an output circuit that includes a wireless power transmitting coil. Measurement circuitry is coupled to the output circuit to help determine whether the wireless power receiving device is present and ready to accept transmission of wireless power. Oscillator circuitry for supplying signals to the output circuitry while making measurements with the measurement circuitry is coupled to the output circuit using an impedance injection network. The impedance injection network includes an inductor and a resistor coupled in series. Control circuitry opens a transistor in the output circuit when making measurements with the measurement circuitry and closes the transistor when transmitting the wireless power signals.

Wireless charging system having measurement circuitry with foreign object detection capabilities

A power converter can be configured to convert an AC input voltage into a regulated DC output voltage while maintaining the input current in phase with the rectified AC input voltage. A control circuit of the power converter may be configured to selectively enable switching of at least one switching device of the power converter responsive to a determination that the input voltage is greater than a threshold voltage and to selectively disable switching of the at least one switching device responsive to a determination that the rectified AC input voltage is less than the threshold voltage. The control circuit may be configured to selectively enable and disable switching using an active burst mode signal having a frequency lower than a switching frequency of the converter. The control circuit may be still further configured to operate at least one switching device of the converter in a zero voltage switching condition.

Active burst ZVS boost PFC converter

A wireless power transfer circuit can include an interphase transformer operatively coupled to a receiver coil, a rectifier, and a load. The receiver coil can be configured to have an alternating current induced therein by a transmitter coil. The interphase transformer can be configured to deliver a current to the load that is twice the current induced in the receiver coil, and the rectifier can be configured to rectify the current delivered to the load. The interphase transformer may be constructed with a center tapped winding structure or a bifilar winding structure, and may be constructed as a planar transformer. The rectifier may be made up of diodes (which may be Schottky diodes) or may be a synchronous rectifier comprised of switching devices such as MOSFETs.

Interphase transformer based rectifier for wireless power transfer

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using output circuitry that includes an array of wireless power transmitting coils that form a wireless charging surface. During wireless power transmission operations, wireless power signals are transmitted from the array of coils to a wireless power receiving device on the charging surface. Inductance measurement circuitry such as impulse response measurement circuitry and other measurement circuitry is coupled to the output circuitry. Control circuitry in the wireless power transmitting device analyzes signals from the measurement circuitry to produce two-dimensional signal profiles across the wireless charging surface and to compare patterns in these signal profiles to predetermined signal patterns associated with the presence of known power receiving equipment on the wireless charging surface. Based on the analysis, charging parameters may be adjusted or other actions taken.

Wireless charging system with object recognition

Growing community of inventors

San Jose, CA, United States of America

Bharat K Patel