An exemplary inductive power transfer system having a transmitter coil and a receiver coil. A transmitter-side power converter having a mains rectifier stage powering a transmitter-side dc-bus and controlling a transmitter-side dc-bus voltage U.sub.1,dc. A transmitter-side inverter stage with a switching frequency f.sub.sw supplies the transmitter coil with an alternating current. A receiver-side power converter having a receiver-side rectifier stage that rectifies a voltage induced in the receiver coil and powering a receiver-side dc-bus and a receiver-side charging converter controlling a receiver-side dc-bus voltage U.sub.2,dc. Power controllers that determine from a power transfer efficiency of the power transfer, reference values U.sub.1,dc*, U.sub.2,dc* for the transmitter and receiver side dc-bus voltages. An inverter stage switching controller controls the switching frequency f.sub.sw to reduce losses in the transmitter-side inverter stage.

A transient current in a rectifier circuit is effectively reduced. In a rectifier circuit, a first rectifier is provided between a first terminal and a second terminal. In the rectifier circuit, when a switch element is turned ON, a primary winding current flows from a power supply to a primary winding of a transformer. When the switch element is turned OFF, a second rectifier current flows from a secondary winding of the transformer to a second rectifier. During a period in which the second rectifier current is flowing, a reverse voltage is applied between the first terminal and the second terminal.

This application provides a controller and control system for a DC/DC converter. The DC/DC converter includes a first switching transistor, a second switching transistor, a first capacitor, and a transformer. The transformer includes an excitation inductor and a transformer leakage inductor. The controller controls the first switching transistor to turn on to form a first closed circuit, where a current in the excitation inductor increases in a first direction; when a preset time period expires, the controller controls the first switching transistor to turn off, so that a voltage at two ends of the second switching transistor decreases; and when the voltage at the two ends of the second switching transistor is a first preset voltage threshold, the controller controls the second switching transistor to turn on to form a second closed circuit. When embodiments of this application are implemented, a turn-on loss in the DC/DC converter can be reduced.

A power conversion device is mounted with a control circuit, a plurality of drive circuits for driving switching elements in response to control signals from the control circuit, and a plurality of power supply circuits for supplying power to the drive circuits on a substrate. The power conversion device has a drive-circuit/power supply-circuit placement and wiring regions of a high current system in which the drive circuits and the power supply circuits are disposed on the substrate are provided for the respective switching elements with isolating regions interposed between the drive-circuit/power supply-circuit placement and wiring regions and the control circuit of a low current system. A gap is formed between the pairs of the drive-circuit/power supply-circuit regions. Power supply transformers are provided for transforming a voltage supplied from the control circuit for the respective power supply circuits in-between the isolating regions.

Routing of a gate signal for controlling a discrete power switching device (such as in an inverter for an electric vehicle drive) is configured to compensate for the common source inductance inherent in the switching device as a result of its integrated circuit packaging. The power device has a gate signal path via a gate pin and a power signal path via first and second power pins, wherein the gate signal path and the power signal path have a first mutual inductance. A circuit board apparatus provides a gate wiring loop juxtaposed with the power signal path, wherein the gate wiring loop and the power signal path have a second mutual inductance substantially canceling the first mutual inductance. The resulting reduction in common source inductance avoids the reductions in switching speed and the increased switching losses otherwise introduced by the common source inductance.

A semiconductor device according to an embodiment includes: a first transistor having a first electrode, a second electrode, and a first control electrode, the first transistor performing a switching operation; a second transistor having a third electrode electrically connected to the second electrode, a fourth electrode, and a second control electrode, the second transistor performing an analog operation; and a third transistor having a fifth electrode electrically connected to the fourth electrode, a sixth electrode, and a third control electrode.

Circuit structures and methods are described for achieving zero voltage switching in flying capacitor converters for both isolated and non-isolated applications. A first method is described in which zero voltage switching is achieved by operating the circuit with a variable frequency so that each switch in its on state remains on until the magnetizing current in a main inductor is reversed to a current magnitude sufficient to drive a zero voltage switching transition for a main switch. A second method is implemented with a main coupled inductor wherein a winding current is reversed and energy in a leakage inductance drives a zero voltage switching transition for a main switch. A third method is implemented with auxiliary inductors, auxiliary switches, and auxiliary capacitors which reverse the current in the auxiliary inductor which provides the necessary energy for driving a zero voltage switching transition for a main switch.

A controller of a switching converter having a switch and an energy storage component. The controller has a hysteresis feedback circuit for generating a hysteresis feedback signal based on an output feedback signal of the switching converter, a first comparison circuit for generating a first comparison signal by comparing the hysteresis feedback signal with a ramp signal, a second comparison circuit for generating a second comparison signal by comparing the output feedback signal with the ramp signal, and a turn-on control circuit. The turn-on control circuit generates a target locked valley number based on a valley pulse signal in response to one or more valleys of a voltage drop across the switch, the first comparison signal, the second comparison signal and a current locked valley number, and further generates a turning on control signal corresponding to the target locked valley number for turning ON the switch.

A converter circuit includes an inverter and a controller. The inverter is configured to receive an input voltage and to convert the input voltage into a primary-side alternating-current (AC) voltage in a first inversion mode or a second inversion mode. Each of a first switch unit and a second switch unit in the inverter includes switches. When the converter circuit works in the first inversion mode, the controller controls switches of the first switch unit and the second switch unit to cooperatively switch on and switch off periodically according to an output voltage corresponding to the primary-side AC voltage. When the converter circuit works in the second inversion mode, the controller controls the first switch unit to operate independently, in which the switches of the first switch unit switch on and switch off periodically.

A multiphase buck converter that includes smart two-phase power stages for reducing switching losses. Each of the smart power stages includes a first high side switch, a second high side switch, a first low side switch, a second low side switch, a switching capacitor, a first inductor, and a second inductor. The exemplary multiphase buck converter includes two such smart power stages and a multiphase controller for generating PWM signals for driving the two smart power stages synchronously.