Texas Instruments Corporation

Apple Inc.

National Semiconductor Corporation

Gianpaolo Lisi

Ali Djabbari

Gerard G Socci

Jianhui Zhang

Kosha Mahmodieh

Nan Liu

Madhusudanan Keezhveedi Sampath

Robert Scritzky

Rajaram Subramonian

Zaki Moussaoui

Jingwei Xu

Swaminathan Sankaran

Florence W Ow

Bradley Allen Kramer

Stephen Christopher Terry

Liquan Tan

Blake R Marshall

Reza Nasiri Mahalati

Ye Li

Rajaram Subramoniam

Dingkun Du

Adam L Schwartz

Sumant Ranganathan

Aidan N Zimmerman

Jeffrey Anthony Morroni

Hao Zhu

Ali Kiaei

Erhan Ozalevli

Joel N Ruscher

Vijayalakshmi Devarajan

Qigen Ji

Mustapha El Markhi

Tuli Luthuli Dake

Antoin J Russell

Zelin Xu

Arash Mehrabi

YiBo Liu

Eric Steven Jol

John Raff

Giovanni Frattini

Nachiket Venkappayya Desai

Rohan Dayal

Liang Chen

Li-Quan Tan

Matthew J Chabalko

Kunal Bhargava

Evan Reutzel

Alex C Yeung

Wei-Hsuan Chen

Tianqi Li

Ahmad R S Bahai

Sakshi Arora

Raj Subramoniam

Yasin Aalipour

Andrew Ronald Chemistruck

Saining Ren

Gaurav Kalra

Bingyao Sun

A wireless power system can include a wireless power transmitter and a wireless power receiver. The transmitter can include a transmit coil, an inverter, and inverter control circuitry that can operate one or more switching devices of the inverter to communicate information to the receiver by controlling a delay between receipt of the burst request pulse and initiating operation of the inverter and/or controlling a polarity of a first pulse of the inverter. The receiver can include a receive coil magnetically coupled to the transmit coil, a rectifier, and rectifier control circuitry that initiates a burst request pulse to initiate operation of a transmitter. The rectifier control circuitry can operate one or more switching devices of the rectifier to communicate information to the transmitter by at least one of short circuiting an LC tank including the receive coil or controlling a polarity of the burst request pulse.

Wireless power transfer with integrated communications

A wireless power transmitter can include a coil, an inverter coupled to the coil, and control circuitry coupled to the inverter that, responsive to receiving a burst request pulse from a wireless power receiver, initiates inverter operation, driving the coil and powering the receiver. The control circuitry can operate inverter switches so bandwidth of the wireless power transfer signal falls within a specified range by: (a) extending a minimum on time of the switches, (b) modifying pulse width modulation (PWM) drive signals supplied to the switches to shape a coil current burst envelope, and/or (c) modifying PWM signal amplitude supplied to the switches. Modifying the PWM drive signals can include using a symmetrical PWM scheme in which the positive and negative pulses are symmetrical in width on a cycle-by-cycle basis or using a complementary PWM scheme in which the positive and negative pulse widths are complementary on a cycle-by-cycle basis.

Frequency management for wireless power transfer

A device in a wireless power system may be operable with a removable accessory such as a case. The device may transmit or receive wireless power through the case while the electronic device is coupled to the case. The case may have a folio shape with a front cover portion that covers the display of the electronic device. The case may have an embedded ferrimagnetic core that relays magnetic flux during wireless power transfer operations. Magnetic alignment structures in the case may position the ferrimagnetic core in the case in a high magnetic flux density region between the power transmitting device and the power receiving device. The ferrimagnetic core relays the magnetic flux between a transmitting coil in the power transmitting device and a receiving coil in the power receiving device. The ferrimagnetic core may be formed in a front portion, a sidewall, or a rear wall of a case.

Accessory with a magnetic relay structure for wireless power transfer

A personal electronic device (e.g., a tablet computer) may be configured to wirelessly charge an accessory (e.g., a stylus) through a display face of the device. At least a portion of the display face may be transparent to facilitate display viewing. A wireless charging assembly disposed within the enclosure may include a core having one or more windings disposed thereon, which may be configured to generate a magnetic flux above the display face to couple to the accessory. The core may be a pot core, a modified pot core, or may have another shape, such as a PQ core. The one or more windings may be disposed on one or more posts of a pot core, or additionally or alternatively, may be disposed on another portion of the core. A metallic shield may be disposed about the wireless charging assembly, thereby surrounding multiple sides of the wireless charging assembly.

Through-display wireless charging

A wireless power system may include an electronic device and a removable case. The electronic device and removable case may include wireless charging coils that are inductively coupled when the electronic device and the removable case are physically coupled. In a first mode, while the removable case is inductively coupled to the electronic device and the electronic device is not connected to a wired power source, a coil in the removable case transmits wireless power signals to the electronic device. In a second mode, while the removable case is inductively coupled to the electronic device and the electronic device is connected to a wired power source, the coil in the removable case receives wireless power signals from the electronic device. In a third mode, the removable case receives wireless power with a first coil and transmits wireless power to the electronic device with a second coil.

Wireless power mode switching

A wireless power transfer system using a resonant rectifier circuit with capacitor sensing. A wireless power transfer system includes a power receiver resonant circuit and a synchronous rectifier. The power receiver resonant circuit includes an inductor and a capacitor connected in series with the inductor. The synchronous rectifier is configured to identify zero crossings of alternating current flowing through the inductor based on voltage across the capacitor, and control synchronous rectification of the alternating current based on timing of the zero crossings.

Resonant rectifier circuit with capacitor sensing

An inductive power transmitter is provided that includes a power transmitting coil which includes transmission circuitry coupled to the power transmitting coil. The inductive power transmitter is configured to produce an inductive power transfer (IPT) signal having an IPT power so that the power transmitting coil generates an IPT field to transfer wireless power to a power receiving coil of an inductive power receiver. The inductive power transmitter includes detection circuitry coupled to the transmission circuitry and is configured to detect one or more indications of a magnetic field strength of a leakage IPT field. The inductive power transmitter includes control circuitry configured to control the transmission circuitry while the transmission circuitry is increasing the IPT power towards a charge level sufficient to charge a battery associated with the inductive power receiver at a target charge rate.

Inductive power transmitter

Embodiments describe a receiving element that includes a ferromagnetic structure axially symmetrical around a central axis disposed along a length of the ferromagnetic structure. The ferromagnetic structure includes a groove region defining two end regions on opposing sides of the groove region, where the groove region has a smaller length than the two end regions. The receiving element also includes an inductor coil wound about the groove region of the ferromagnetic structure and in between the two end regions.

Attachment devices for inductive interconnection systems

Inductive interconnection system

Hybrid connectors that may transfer power and data with a variety of electronic devices having different types of connector interfaces, may consume a minimal amount of surface area, depth, and volume in an electronic device, and may be readily manufactured.

Hybrid connector

An example apparatus includes a feedback loop to: change a direction value when a second current value is greater than a first current value, the second current value being obtained after the first current value; and maintain the direction value when the second current value is less than the first current value. When the direction value corresponds to a first direction value, a summer increases a reference signal by a step size. When the direction value corresponds to a second direction value different than the first direction value, the summer decrease the reference signal by the step size.

Methods and apparatus to increase efficiency for wireless power transfer

In described examples, an inductive structure includes first and second inductive coils to conduct respective first and second common mode currents induced by a common mode transient between: a first ground coupled to a connection between the first and second inductive coils; and a galvanically isolated second ground.

Inductive structures with improved common mode transient immunity

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Los Gatos, CA, United States of America

Gianpaolo Lisi