Microchip Technology Inc.

Alex Dumais

Santosh Bhandarkar

Bryan Kris

Stephen Bowling

Andreas Reiter

Mike Catherwood

Dave Mickey

Brian Fall

Igor Wojewoda

Yong Yuenyongsgool

Thomas S Spohrer

John Day

Jason Tollefson

Justin Oshea

Vincent Sheard

Calum Wilke

Calum Wilkie

Sankar Rangarajan

Jim Pepping

Tibor Futo

A wireless power transmitter and methods to: determine a transmitter frequency bandwidth of the wireless power transmitter when no wireless power receiver is inductively coupled with the wireless power transmitter; determine a transmitter-receiver frequency bandwidth when a wireless power receiver is inductively coupled with the wireless power transmitter; compare the transmitter-receiver frequency bandwidth and the transmitter frequency bandwidth; and detect a foreign object near the transmit coil based on the comparison of the transmitter-receiver frequency bandwidth and the transmitter frequency bandwidth.

Foreign object detection by frequency bandwidth comparison

Foreign object detection and related apparatuses, methods, and systems are disclosed. An apparatus includes one or more inductive coils to wirelessly couple with another inductive coil, a series capacitor electrically connected in series with the one or more inductive coils, and a controller to determine a coil current through the one or more inductive coils responsive to a capacitor voltage potential difference across the series capacitor and determine a coil power responsive to the determined coil current and a coil voltage potential difference across the one or more inductive coils.

Foreign object detection and related apparatuses, methods, and systems

A fault event monitor and filter having a digital comparator receiving a digital input value, wherein the digital comparator generates a plurality of outputs based on programmable threshold input values, a first counter coupled to a first output of the plurality of outputs of the digital comparator, a second counter coupled to a second output of the plurality of outputs of the digital comparator, and an output controller with a first input coupled to an output of the first counter and with a second input coupled to an output of the second counter, wherein the output controller to generate a fault event signal based at least partially on signals received from the first and second counters.

Programmable fault violation filter

A device including an input to receive a clock signal, a ramp start program register, a ramp start active register, a ramp stop program register, a ramp stop active register, a ramp slope program register, a ramp slope active register, an update controller, the update controller to update, based on a programmable condition, respectively, the ramp start active register contents, the ramp stop active register contents and the ramp slope active register contents, and a ramp controller to generate a ramp signal, the ramp signal to begin at the value reflective of the ramp start active register contents, the ramp signal to change value at each cycle of the clock signal based on the value reflective of the ramp slope active register contents, and the ramp signal to stop at the value reflective of the ramp stop active register contents.

System and methods for ramp control

Object detection for wireless power transmitters and related systems, methods, and devices are disclosed. A controller for a wireless power transmitter is configured to receive a measurement voltage potential responsive to a tank circuit signal at a tank circuit, provide an alternating current (AC) signal to each of the plurality of transmit coils one at a time, and determine at least one of a resonant frequency and a quality factor (Q-factor) of the tank circuit responsive to each selected transmit coil of the plurality of transmit coils. The controller is also configured to select a transmit coil to use to transmit wireless power to a receive coil of a wireless power receiver responsive to the determined at least one of the resonant frequency and the Q-factor for each transmit coil of the plurality of transmit coils.

Low power object detection in multi-coil wireless charging systems and related systems, methods, and devices

Object detection in wireless power systems and related system, methods, and devices are disclosed. A controller for a wireless power transmitter includes a measurement voltage potential input terminal and a processing core. The processing core is to determine an average of peak to peak amplitude differences present in sampled measurement voltage potentials for each of the plurality of transmit coils, determine a lowest average of the peak to peak amplitude differences, and select a transmit coil corresponding to the lowest average of the peak to peak amplitude differences to transmit wireless power to a receive coil of a wireless power receiver. A wireless power system includes a tank circuit selectively including any one of a plurality of transmit coils.

Transmit coil selection responsive to average peak to peak measurement voltage potentials and related apparatuses and method

Apparatuses and methods related to a converter are disclosed. An apparatus includes a converter and a controller. The converter converts an input voltage potential to an output voltage potential. The input voltage potential and the output voltage potential include direct current (DC) voltage potentials. The controller generates pulse width modulation (PWM) signals responsive to a duty cycle control signal, controls the converter via the PWM signals in a buck mode when the duty cycle control signal is less than a predetermined maximum buck value, and controls the converter via the PWM signals in a cascaded buck-boost mode (CBB mode) when the duty cycle control signal is greater than the predetermined maximum buck value. A duty cycle of at least a portion of the PWM signals transitions linearly with the duty cycle control signal from the buck mode to the CBB mode.

Converters and related apparatuses and methods

Various methods relate to digital demodulation for wireless power transmission. A method of operating a wireless power transmitter includes transmitting, with a transmitter coil of a wireless power transmitter, power to a receiver coil of a wireless power receiver. The method also includes sampling one or more electrical signals of the wireless power transmitter. The one or more electrical signals are modulated responsive to alteration of electrical conditions at the wireless power receiver. The method further includes digitally demodulating the sampled one or more electrical signals using a digital filter to obtain a communication from the wireless power receiver. The digital filter includes at least two low pass filter stages that each filter out a fundamental frequency used for the transmission of the power to the receiver coil.

Digital demodulation for wireless power transfer and related methods

Systems, methods, and devices related to a converter of a wireless power transmitter are disclosed. A controller for a wireless power transmitter is configured to sample an output voltage potential to produce a digital output voltage potential, determine an error between an output reference voltage potential and the digital output voltage potential, filter the error to determine a filtered error, and apply an adaptive gain to the filtered error to determine a duty cycle control signal. The adaptive gain is determined responsive to a converter input voltage potential of the converter of the wireless power transmitter. The controller is further configured to determine a controller output including buck pulse width modulation (PWM) signals and boost PWM signals based on the duty cycle control signal, the controller output configured to control the converter of the wireless power transmitter.

Converters for wireless power transfer and related systems, methods, and devices

Various embodiments relate to digital demodulation for wireless power transmission. A wireless power transmitter includes a transmitter coil and a controller. The transmitter coil is configured to wirelessly couple to a receiver coil of a wireless power receiver to transfer power to the wireless power receiver responsive to a coil current applied to the transmitter coil. The wireless power receiver is configured to modulate at least one electrical condition of the wireless power receiver to modulate the coil current at the transmitter coil. The controller is configured to sample one or more electrical signals of the wireless power transmitter, and digitally demodulate the sampled one or more electrical signals to obtain a communication received from the wireless receiver responsive to the modulation of the at least one electrical condition of the wireless power receiver.

Digital demodulation for wireless power transfer and related systems, methods, and devices

In a wireless power transfer system for supplying power to a wireless device, e.g., charging a battery, wireless power transmitter coil voltage is used in place of coil current for communication and power control reference. The transmitter coil voltage waveforms provide phase information, with reference to the pulse width modulation (PWM) waveforms, that can be used to demodulate digital packet communication from a wireless power receiver used to provide a voltage to a device. The DC voltage amplitude of the wireless power transmitter coil is used for controlling the power injected to the wireless power receiver coil, while the phase of the transmitter coil voltage PWM signal is used for demodulation of signal packets from the wireless power receiver to control the transmitter coil voltage and thereby wireless power transfer to the power receiver.

Wireless power transfer based on transmitter coil voltage sensing

Adaptive slope compensation for current mode control in a switch mode power supply converter is computed for every switching cycle based upon the input voltage and duty-cycle whereby the quality factor is maintained at a constant value. A digital signal processing (DSP) capable microcontroller comprises a voltage loop compensator and generates a desired current reference for every switching cycle. Slope calculations are adapted for switching frequency, inductance value, current circuit gain, etc. The slope calculation result is applied to a pulse-digital-modulation (PDM) digital-to-analog converter (DAC) capable of changing its output levels at a very fast rate compared to the power supply switching frequency whereby the required current slope is provided within the switching period. Actual inductor current may be used to compare against the slope reference, thereby taking care of changes in the inductance values under load. The slope levels are automatically changed when the switching frequency is changed.

Adaptive slope compensation for current mode control

A circuit arrangement, signal processor, and method for interleaved switched boundary mode power conversion are disclosed. The circuit arrangement comprises at least an input for receiving an alternating input voltage from a power supply; an output to provide an output voltage to a load; a first interleaved circuit comprising: a first energy storage device; and a first controllable switching device; and one or more secondary interleaved circuits, each comprising: a secondary energy storage device; and a secondary controllable switching device; and a signal processor. The signal processor is connected to the controllable switching devices and comprises at least a first switching cycle controller, configured for cycled zero-current switching operation of the first controllable switching device; and one or more secondary switching cycle controllers, configured for cycled zero-current switching operation of the one or more secondary controllable switching devices The signal processor is configured to disable one or more of the interleaved circuits when the alternating input voltage is lower than a first threshold voltage to reduce the zero-crossing time.

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Gilbert, AZ, United States of America

Alex Dumais