Abstract: A wireless power transfer device can include a coil that couples to a corresponding coil of a counterpart device to facilitate wireless power transfer, a power converter coupled to the coil, and controller and communication circuitry that monitors one or more observable parameters associated with the wireless power transfer to detect a presence of a foreign object that is not the counterpart device and control the power converter responsive to detection of a foreign object. The controller and communication circuitry can perform foreign object detection based on power accounting that includes estimating friendly metal losses associated with the counterpart device. The controller and communication circuitry can receive from the counterpart device friendly metal loss modeling parameters associated with the counterpart device, the modeling parameters including one or more coefficients relating to a wireless power transfer current and one or more coefficients relating to a wireless power transfer voltage.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to the wireless power receiving device. The wireless power transmitting device determines whether an external object is present. The external object may be a foreign object such as a coin or paperclip or may be a wireless power receiving device. External objects are detected using quality-factor measurements. Wireless communications are used to discriminate between foreign objects and wireless power receiving devices. Quality factor measurements may be compensated for aging and temperature effects using temperature measurements and compensation factors based on frequency and measured resistance.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to the wireless power receiving device. The wireless power transmitting device determines whether an external object is present. The external object may be a foreign object such as a coin or paperclip or may be a wireless power receiving device. External objects are detected using quality-factor measurements. Wireless communications are used to discriminate between foreign objects and wireless power receiving devices. Quality factor measurements may be compensated for aging and temperature effects using temperature measurements and compensation factors based on frequency and measured resistance.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include ASK decoding circuitry. An inverter controller may supply control signals to an inverter based on a clock signal. To improve wireless transmission at various frequencies of interest, the clock signal used by the inverter controller may be dithered using a modulating signal. To mitigate bit errors in ASK decoding caused by the dithering of the clock signal in the wireless power transmitting device, ASK communication receiving circuitry in the wireless power transmitting device may receive information regarding the modulating signal used to dither the clock signal. The ASK communication receiving circuitry may receive a clock signal that has been dithered using the modulating signal, dither an analog-to-digital converter sampling rate using the modulating signal, or include notch filtering circuitry with parameters determined based on the modulating signal.

Abstract: A wireless charging system having a power transmitter may wirelessly transfer power to a power receiver. Shield saturation, such as saturation of a ferrite structure, in the wireless power receiver may occur under some operating conditions. Saturation can lead to disruptive oscillations in power transfer. The power transmitting may include control circuitry for detecting and mitigating saturation.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to the wireless power receiving device. The wireless power transmitting device determines whether an external object is present. The external object may be a foreign object such as a coin or paperclip or may be a wireless power receiving device. External objects are detected using quality-factor measurements. Wireless communications are used to discriminate between foreign objects and wireless power receiving devices. Quality factor measurements may be compensated for aging and temperature effects using temperature measurements and compensation factors based on frequency and measured resistance.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to the wireless power receiving device. The wireless power transmitting device determines whether an external object is present. The external object may be a foreign object such as a coin or paperclip or may be a wireless power receiving device. External objects are detected using quality-factor measurements. Wireless communications are used to discriminate between foreign objects and wireless power receiving devices. Quality factor measurements may be compensated for aging and temperature effects using temperature measurements and compensation factors based on frequency and measured resistance.

Abstract: A capacitive sensing array includes a first transmitter electrode, a plurality of first receiver electrodes, a second transmitter electrode, and a plurality of second receiver electrodes disposed in a first row of the array. The first transmitter electrode is disposed in a first column of the array and is coupled to a first transmitter channel. The first receiver electrodes are disposed in a second column of the array, adjacent the first transmitter electrode, and are coupled to a respective one of a plurality of first receiver channels. The second transmitter electrode is disposed in a third column of the array and is coupled to a second transmitter channel. The second receiver electrodes are disposed in a fourth column of the array, adjacent the second transmitter electrode, and are coupled to a respective one of the first receiver channels.

Abstract: A wireless charging system having a power transmitter may wirelessly transfer power to a power receiver. Shield saturation, such as saturation of a ferrite structure, in the wireless power receiver may occur under some operating conditions. Saturation can lead to disruptive oscillations in power transfer. The power transmitting may include control circuitry for detecting and mitigating saturation.

Abstract: 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.

Abstract: 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.

Abstract: A wireless power system has a wireless power transmitting device with a wireless power transmitting coil and an inverter. The inverter and wireless power transmitting coil are used to transmit wireless power signals. The wireless power system also has a wireless power receiving device configured to receive the wireless power signals using a wireless power receiving coil. A rectifier in the wireless power receiving device rectifies alternating-current signals from the wireless power receiving coil and produces corresponding direct-current power. Power loss calculations may be used to help determine whether a foreign object might be present in the vicinity of a coupled wireless power transmitter and receiver. In an ecosystem with multiple models of transmitter and multiple models of receiver, model-dependent scaling factors may be maintained and exchanged between a given coupled transmitter and receiver pair to allow accurate power loss estimates to be made.

Abstract: Power may be transmitted wirelessly between electronic devices. Devices such as cellular telephones, wireless charging pucks, and other equipment may have wireless power circuitry with coils. The wireless power circuitry may have inverter circuitry and rectifier circuitry. The inverter circuitry and a coil that receives alternating-current signals from the inverter circuitry may be used to transmit wireless power signals. Wireless power signals received by a coil in a mated device may be rectified using the rectifier circuitry in that device to produce direct-current power. To align first and second devices for power transfer between their coils, devices may be provided with alignment magnets. The alignment magnets may be configured to permit a first device to be mated back-to-back with a second device such as a second device of the same type as the first device.

Abstract: An accessory for improving wireless power transfer efficiency in a wireless power transfer system can include a magnetic (e.g., ferrite) core dimensioned and positioned so as to reduce flux coupling from the PTx winding into friendly metal of the PRx and/or to enhance flux coupling from the PTx winding to the PRx winding. The core may define an aperture corresponding to an outer dimension (e.g., outer diameter) of the PRx winding. The core may further have an outer dimension selected to intercept sufficient flux to reduce flux coupling into the friendly metal of the PRx, such as an outer dimension corresponding to an outer dimension (e.g., outer diameter) of the PTx winding. The accessory may be a case for the PRx device or may be configured to be affixed to the face of the PTx device and may also include one or more alignment fixtures.

Abstract: A wireless charging system having a power transmitter may wirelessly transfer power to a power receiver. Shield saturation, such as saturation of a ferrite structure, in the wireless power receiver may occur under some operating conditions. Saturation can lead to disruptive oscillations in power transfer. The power transmitting may include control circuitry for detecting and mitigating saturation.

Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.

Abstract: Disclosed is an input device, comprising a touch sensor and a processing system. The touch sensor includes a touch sensing region and a plurality of pixels in the touch sensing region. The processing system is coupled to the touch sensor and comprises circuitry configured to: determine that a touch has occurred on a touch sensor; for each pixel included in the touch, receive touch information from the touch sensor; for each pixel included in the touch, determine a pixel response value for the pixel; and, compute a touch-based metric based on one or more pixel response values, wherein a model is used to perform behavioral authentication based on the touch-based metric.

Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.

Abstract: A capacitive sensing array includes a first transmitter electrode, a plurality of first receiver electrodes, a second transmitter electrode, and a plurality of second receiver electrodes disposed in a first row of the array. The first transmitter electrode is disposed in a first column of the array and is coupled to a first transmitter channel. The first receiver electrodes are disposed in a second column of the array, adjacent the first transmitter electrode, and are coupled to a respective one of a plurality of first receiver channels. The second transmitter electrode is disposed in a third column of the array and is coupled to a second transmitter channel. The second receiver electrodes are disposed in a fourth column of the array, adjacent the second transmitter electrode, and are coupled to a respective one of the first receiver channels.

Abstract: A method for performing navigation (NAV) operations using a sensor device comprising a plurality of transmitter electrodes includes: receiving, at an input sensing region of the sensor device, an input object; scanning, by the sensor device, the input object, wherein the scanning comprises driving a first subset of transmitter electrodes for low-resolution scanning and driving a second subset of transmitter electrodes for high-resolution scanning; and determining, by the sensor device, an input object motion based at least in part on the scanning.