Abstract: A wireless power transmitting device may transmit wireless power signals to a wireless power receiving device. The wireless power receiving device may have a housing. A display may be mounted in the housing on a front face of the device. A rear housing wall on a rear face of the device may be provided with a wireless power receiving solenoid. The solenoid may have a linear strip shape that extends along a longitudinal axis. The longitudinal axis may extend perpendicularly to a wrist strap coupled to the housing. The wireless power receiving solenoid may have opposing first and second ends. The wireless power transmitting device may have a wireless power transmitting solenoid with opposing first and second ends that are configured to transmit the wireless power signals respectively to the first and second ends of the wireless power receiving device when the wireless power receiving solenoid is within the cradle.

Abstract: This disclosure relates to the inductive charging of portable electronic devices. In particular, a charging assembly is disclosed that allows a portable electronic device to be charged in multiple orientations with respect to a charging device. The charging assembly includes two or more separate inductive receiving coils. The inductive receiving coils can be arranged orthogonally with respect to one another by wrapping one or more secondary receiving coils around a ferritic core having two legs extending in different directions from a joint region. By orienting the receiving coils orthogonally with respect to one another, the likelihood of at least one of the receiving coils being aligned with a charging field emitted by a charging device increases substantially.

Abstract: A transmitter device is configured to transfer energy to multiple receiver devices. The transmitter device includes multiple transmitter coils, and a shared power converter is coupled to each transmitter coil. The shared power converter includes a leading half bridge and multiple trailing half bridges. Each transmitter coil is coupled between the leading half bridge and a respective one of the trailing half bridges. The shared power converter is dynamically configurable in that the leading half bridge may be coupled to multiple trailing half bridges when energy is to be transferred wirelessly to two or more receiver devices. The leading half bridge simultaneously operates with each trailing half bridge as an independent full-bridge phase shift inverter. A signal supplied to each transmitter coil is independently regulated by controlling a phase shift of a respective trailing half bridge with respect to the leading half bridge.

Abstract: A wireless power transmitting device may have an array of transmitting coils to transmit power wirelessly to a wireless power receiving device having an array of wireless power receiving coils. The receiving device may have a rectifier that receives alternating-current signals from the wireless power receiving coils and provides corresponding rectified direct-current voltage signals to a capacitor and other circuitry. The rectifier circuitry may include bridge circuits each of which is coupled between a respective coil in the array of wireless power receiving coils and the capacitor. The wireless power transmitting coils may be arranged in a hexagonally tiled array. The wireless power receiving coils may include first, second, and third coils that are aligned with respective vertices in an equilateral triangle having sides with lengths equal to half of the center-to-center spacing of the hexagonally tiled transmitting coils.

Abstract: A wireless power transmitting device may have control circuitry that supplies drive signals to a coil to produce wireless power signals. The wireless power receiving device may have a coil that receives the transmitted wireless power signals from the wireless power transmitting device. The wireless power receiving device may have a rectifier that rectifies signals received by the coil in the wireless power receiving device and that provides a rectified voltage to a capacitor. A charger in the wireless power receiving device may charge a battery in the device using the rectified voltage. When it is desired to convey information to the wireless power transmitting device, the wireless power transmitting device may cease the transmission of wireless power and the wireless power receiving device may modulate transistors in the rectifier to transmit data to the wireless power transmitting device.

Abstract: An embodiment of a circuit includes a circuit module and an inductor disposed over and electrically coupled to the module. Disposing the inductor over the module may reduce the area occupied by the circuit as compared to a circuit where the inductor is disposed adjacent to the module, or to a circuit where the inductor is disposed in the module adjacent to other components of the module. Furthermore, disposing the inductor outside of the module may allow one to install or replace the inductor.

Abstract: This disclosure relates to improved designs for phase-shift power converters, and, in particular, full bridge converters. Phase-shift power converters may lose Zero-Voltage-Switching (ZVS) under some load conditions, e.g., light load conditions—which can result in large switching losses. In order to avoid these losses, additional LC tank circuits may be added into the system to generate an amount of negative current needed to maintain ZVS. However, permanently adding such LC tank circuits into the system will reduce the system's efficiency. By intelligently adjusting the number (and particular combination) of LC tank circuits included in the system at a given time, ZVS may be maintained under all load conditions, while the impact of the additional LC tank circuits on the converter's overall efficiency may be limited, e.g., by employing the minimum number of LC tank circuits for the minimum amount of time needed to maintain ZVS.

Abstract: This disclosure relates to power converters capable of providing multiple output voltage levels. With respect to USB-C adapter design, the converter's output may need to be changed between different voltage levels, e.g., a low voltage (such as 5V, 10V), an intermediate voltage (such as 12V, 20V), or a high voltage (such as 20V, 40V)—based on the charging device's request. By using a tapped-winding transformer, the turns-ratio of a flyback transformer may be intelligently selected for high output voltage ranges, thus enabling the duty cycle to be kept the same for the low and intermediate voltage output levels. The flyback converter would then only need to accommodate the intermediate and high output voltages. For high output voltages, a switch may be activated to put the two windings of the transformer in series; for lower output voltages, the switch may be turned off, such that only one winding is used.

Abstract: An embodiment of a circuit includes a circuit module and an inductor disposed over and electrically coupled to the module. Disposing the inductor over the module may reduce the area occupied by the circuit as compared to a circuit where the inductor is disposed adjacent to the module, or to a circuit where the inductor is disposed in the module adjacent to other components of the module. Furthermore, disposing the inductor outside of the module may allow one to install or replace the inductor.

Abstract: An apparatus for charging a plurality of series connected battery cells, includes a first and second input terminals for providing a charging voltage to the plurality of series connected battery cell. A transformer includes a primary side associated with the charging voltage and a secondary side includes a plurality of portions. Each of the plurality of portions is connected across at least one of the plurality of series connected battery cell. A switch in series between each of the plurality of portions of the secondary side and the at least one of the plurality of series connected battery cells increases an impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a first state and decreases the impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a second state.

Abstract: An apparatus for charging a plurality of series connected battery cells, includes a first and second input terminals for providing a charging voltage to the plurality of series connected battery cell. A transformer includes a primary side associated with the charging voltage and a secondary side includes a plurality of portions. Each of the plurality of portions is connected across at least one of the plurality of series connected battery cell. A switch in series between each of the plurality of portions of the secondary side and the at least one of the plurality of series connected battery cells increases an impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a first state and decreases the impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a second state.

Abstract: An apparatus for charging a plurality of series connected battery cells, includes a first and second input terminals for providing a charging voltage to the plurality of series connected battery cell. A transformer includes a primary side associated with the charging voltage and a secondary side includes a plurality of portions. Each of the plurality of portions is connected across at least one of the plurality of series connected battery cell. A switch in series between each of the plurality of portions of the secondary side and the at least one of the plurality of series connected battery cells increases an impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a first state and decreases the impedance between the portion of the secondary side and the associated one of the plurality of series connected battery cells in a second state.

Abstract: A system and method for regulating power flow and limiting inductor current in a bidirectional direct current (DC)-to-DC converter is provided. In one aspect, a feedback circuit is provided to control power flow and/or limit inductor current based on the input/output voltage and/or current conditions in the bidirectional DC-DC converter. During a boost mode of operation, the duty cycle of a low-side switch within the bidirectional DC-DC converter is reduced, based on an analysis of the high-side voltage and positive inductor current. Further, during a buck mode of operation, the duty cycle of the low-side switch is increased, based on an analysis of the low-side voltage and negative inductor current. Moreover, the duty cycle of the low-side switch is adjusted, such that, the high-side voltage, low-side voltage and inductor current (in both directions) do not exceed preset threshold and the bidirectional DC-DC converter returns to a steady state.

Abstract: A circuit, device, and method for controlling a buck-boost circuit includes a bootstrap capacitor voltage regulator circuit and a comparator circuit. The bootstrap capacitor voltage regulator circuit is electrically coupled to a buck-mode bootstrap capacitor of the buck-boost converter and to a boost-mode bootstrap capacitor of the buck-boost converter. The comparator circuit is configured to control the bootstrap capacitor voltage regulator circuit to maintain a voltage of the bootstrap capacitors above a reference threshold voltage by transferring an amount energy from one of the bootstrap capacitors to the other bootstrap capacitors based on the particular mode of operation of the buck-boost converter.

Abstract: An embodiment of a controller for a multidirectional signal converter is operable to cause the converter to regulate a first signal at a first converter node, and to have a switch timing that is independent of a direction of power transfer between the first converter node and a second converter node. For example, in an embodiment, such a controller may be part of a bidirectional voltage converter that handles power transfer between two loads. Such a voltage converter may have improved conversion efficiency and a smaller size and lower component count as compared to a conventional multidirectional voltage converter. Furthermore, such a voltage converter may be operable with a common switching scheme regardless of the direction of power transfer, and without the need for an indicator of the instantaneous direction of power flow.

Abstract: A regulator controller which controls conversion of an input voltage to an output voltage, including a switching regulator, a low dropout (LDO) regulator, and a mode controller. The switching regulator develops a pulse control signal to regulate the output voltage when enabled. The LDO regulator also regulates the output voltage when enabled. The mode controller enables or disables the switching regulator and the LDO regulator based on a load condition. The switching regulator is enabled and the LDO regulator is disabled during normal operation. The LDO regulator is enabled when the low load condition is detected, such as a skipped pulse on the pulse control signal. The switching regulator is disabled when the pulse control signal reaches a minimum level. The LDO regulator is disabled and the switching regulator is re-enabled based on threshold conditions of the current output of the LDO regulator.

Abstract: An EMI reduction network for a converter, the converter including upper and lower power switches provided between an input voltage node and a reference node. An inductance is coupled between the input voltage node and the upper switch at a first node, a capacitance and an auxiliary power switch are coupled in series between the first and reference nodes, and a controller is provided to control switching. The controller switches the upper switch based on a PWM signal. The controller keeps the lower switch turned on until the phase node goes positive while the upper switch is on. The controller turns the auxiliary switch on after the lower power switch is turned off and turns the auxiliary switch off after the upper power switch is turned off. The lower and auxiliary switches may be zero voltage switched, and the upper switch may be zero current switched.

Abstract: An apparatus for charging a plurality of series connected battery cells includes first and second input terminals for providing a charging voltage to the plurality of series connected battery cells. A transformer includes a primary side associated with the charging voltage and a secondary side including a plurality of portions. Each of the plurality of portions connected across at least two of the plurality of series connected battery cells. A first switch in series between each of the plurality of portions of the secondary side and a first battery cell of the at least two of the plurality of series connected battery cells provides a charging current to the first battery cell during a first portion of a cycle of a current in the primary side of the transformer.

Abstract: An embodiment of a multidirectional signal converter includes first and second converter nodes, a transformer, and first and second stages. The transformer includes first and second windings, and the first stage is coupled between the first converter node and the first winding of the transformer. The second stage includes a first node coupled to the second converter node, a second node coupled to a node of the second winding of the transformer, and a filter node, is operable as a boost converter while current is flowing out from the second converter node, and is operable as a buck converter while current is flowing out from the first converter node. For example, in an embodiment, such a multidirectional signal converter may be a bidirectional voltage converter that handles power transfer between two loads. Such a voltage converter may have improved conversion efficiency and a smaller size and lower component count as compared to a conventional multidirectional voltage converter.

Abstract: An apparatus includes a buck boost converter for generating a regulated output voltage responsive to an input voltage. The buck boost converter includes an inductor, a first pair of switching transistors responsive to a first PWM signal and a second pair of switching transistors responsive to a second PWM signal. An error amplifier generates an error voltage responsive to the regulated output voltage and a reference voltage. A control circuit generates the first PWM signal and the second PWM signal responsive to the error voltage and a sensed current voltage responsive to a sensed current through the inductor. The control circuit controls switching of the first pair of switching transistors and the second pair of switching transistors using the first PWM signal and the second PWM signal responsive to the sensed current through the inductor and a plurality of offset error voltages based on the error voltage.