Maxim Integrated Products, Inc.

Integrated Device Technology, Inc.

Apple Inc.

Other

Mehmet Kadri Nalbant

Alexei Elias Kosut

Alireza Safaee

Zaid A AbuKhalaf

Juan Carlos Pastrana

Jukka-pekka J Sjoeroos

James J Locascio

Francesco Bezzi

Wireless power transfer devices may be configured to negotiate with each other to operate. For example, a wireless power standard may provide for various levels of power delivery, various frequencies for power transfer, various operating voltages, and so forth. There may be instances in which it is desirable to provide wireless power transfer devices (both PTx and PRx) that are capable of enhanced performance when paired with a compatible device. For example, devices can be configured to operate at higher or more granular power levels, different frequencies, and so forth.

Enhanced wireless power transfer

A multimode receiver can include on or more of an over-voltage protection circuit or a high frequency mode switch. As such, some embodiments of a multi-mode receiver includes a rectifier; a high frequency circuit coupled to the rectifier; a low frequency circuit coupled to the rectifier; and a switching circuit coupled to disable at least a portion of the low frequency circuit while the multi-mode receiver operates in high frequency mode. In some embodiments, the multimode receiver further includes a high-voltage protection circuit coupled to the high frequency circuit that detunes the high frequency circuit when a high-voltage condition is detected.

Multimode wireless power receiver circuit

A wireless power transmitter comprises a bridge inverter including a first switch and a second switch coupled together with a first switching node therebetween, and a first capacitor coupled to the first switching node. The transmitter further includes control logic configured to control the first switch and the second switch according to an operating frequency to generate an AC power signal from a DC power signal, and a resonant tank operably coupled to the first switching node of the bridge inverter, the resonant tank configured to receive the AC power signal and generate an electromagnetic field responsive thereto. A method for operating the wireless power transmitter and a method for making the wireless power transmitter are also disclosed.

Wireless power transmitter having low noise and high efficiency, and related methods

A wireless power transmission system is presented. In some embodiments, a transmission unit includes a first inductor with a center tap, a first end tap, and a second end tap; a pre-regulator coupled to provide current to the center tap; a switching circuit coupled to the first end tap and the second end tap, the switching circuit alternately coupling the first end tap and the second end tap to ground at a frequency; and a resonant circuit magnetically coupled to the first inductor, the resonant circuit wirelessly transmitting power. In some embodiments, the switching circuit can be formed of FETs. The current provided to the center tap can be controlled in response to current sensors.

Wireless power transmitter

In accordance with some embodiments, a transmitter for wireless transfer includes a rectifier that receives an AC voltage and provides a DC voltage; a capacitor that receives and smooths the DC voltage; a regulator that receives the DC voltage and outputs an input voltage; and a wireless transmitter that receives the input voltage and transmits wireless power.

High efficiency wireless power system

A wireless power transmission system is presented. The wireless power circuit includes an adaptive transmitter coupled to a transmit coil; a receive coil in interaction with the transmit coil, the receive coil being thin and having an inner diameter large enough to accommodate sensors of a wearable device; and a receive circuit receiving power from the receive coil.

Adaptive resonant topology application in wearable devices

The present disclosure relates wireless power transfer. In some embodiments, DC power is received through one or more inductors and switched to provide alternating current through a TX coil with a pair of power FETs coupled between opposite sides of the TX coil and ground such that current flows through one of the pair of FETs at a time. In some embodiments, the pair of FETs can be driven in adaptive resonant mode to operate at a resonance. In some embodiments, the pair of FETs are driven at a particular frequency.

Wireless power system

A power circuit includes a plurality of LED strings, each LED string having multiple LEDs connected in series. A plurality of magnetic amplifiers, reset current sources, and a control circuit are used to drive each LED string with equal current and to independently regulate the amount of voltage supplied to each LED to maximize efficiency. One magnetic amplifier, one reset current source, and one current sink are dedicated to each LED string. The control circuit measures the voltage drop across each LED string and determines an amount of reset control current in response to the measured voltage drop. The reset control current is supplied by the reset current source to the magnetic amplifier dedicated to the regulated LED string. The amount of reset control current supplied to the magnetic amplifier dictates the amount of voltage supplied to the LED string.

Magnetic amplifier assisted LED constant current sink overhead voltage regulation

A battery cell balancing system includes N switching circuits connected to first terminals and second terminals of N battery cells, respectively, where N is an integer greater than one. A first transformer includes a first core and N sets of windings wound around the first core. The N sets of windings are connected to the N switching circuits, respectively. A first control module controls switching of the N switching circuits to reverse first connections between the first terminals and the second terminals of the N battery cells and the N sets of windings, respectively, at a first frequency to balance charge levels of the N battery cells.

Active cell balancing

A power circuit include a plurality of LED strings, each LED string having multiple LEDs connected in series. A plurality of magnetic amplifiers, reset current sources, and a control circuit are used to drive each LED string with equal current and to independently regulate the amount of voltage supplied to each LED to maximize efficiency. One magnetic amplifier, one reset current source, and one current sink are dedicated to each LED string. The control circuit measures the voltage drop across each LED string and determines an amount of reset control current in response to the measured voltage drop. The reset control current is supplied by the reset current source to the magnetic amplifier dedicated to the regulated LED string. The amount of reset control current supplied to the magnetic amplifier dictates the amount of voltage supplied to the LED string.

A boost regulator is provided that has increased efficiency. The increased efficiency is provided by incorporating a sensing circuit that senses when the current in the boost regulator's inductor is near zero or when the voltage at its switching node is near zero or virtual ground. A switching signal is provided to the boost regulator's switching transistor when the near zero current or voltage is sensed. Switching at the near zero current or voltage moment (the 'critical conduction moment') helps to eliminate or minimize the power loss associated with switching the transistor at a time other than during the critical conduction moment.

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Cupertino, CA, United States of America

Mehmet Kadri Nalbant