A resonance voltage attenuation detection circuit detects attenuation of a resonance voltage of a winding of a transformer. The resonance voltage attenuation detection circuit includes a first voltage comparator circuit and a time-out circuit. The first voltage comparator circuit compares a voltage of the winding with a predetermined first voltage. The time-out circuit performs clocking operation in accordance with an output of the first voltage comparator circuit. The time-out circuit outputs an attenuation detection signal when the time-out circuit has clocked a preset period which is shorter than a time required for a peak voltage of the winding to be attenuated from the first voltage to a predetermined second voltage lower than the first voltage.

A power supply includes an inverter configured to direct current (DC) power into alternating current (AC) power, an impedance matching circuit configured to supply the AC power to a load; and a controller configured to adjust disposition of a powering period, in which the AC power is output, and a freewheeling period, in which the AC power is not output, to adjust a power amount of the power supplied to the load through the impedance matching circuit by the inverter.

This application provides a switching conversion circuit, including: a power module, supplying power to a switching conversion module and an IC controller; and the switching conversion module is an asymmetrical half-bridge flyback structure and includes at least a first switching transistor, a second switching transistor, a first capacitor, and a transformer. The transformer includes a first secondary-side winding and a second secondary-side winding, and the first secondary-side winding of the transformer is coupled to a load. The IC controller turns on the first switching transistor or the second switching transistor based on a value of a first voltage, so that the switching conversion module enters an operating state to supply power to the load; and turns off the first switching transistor and the second switching transistor based on a value of a second voltage, so that the switching conversion module stops supplying power to the load.

A zero-voltage switching (ZVS) buck-boost converter to reduce or even minimize switching power loss and improve EMI performance is described herein. The buck-boost converter may include an auxiliary path to generate an auxiliary current to charge and discharge respective nodes in the converter during select switching times. The converter may operate in buck-boost mode, buck mode, or boost mode. Moreover, the auxiliary path may include components, such as a pair of power switches and an inductor, arranged in a symmetrical fashion so that the converter may achieve ZVS in bidirectional operation as well.

A switched capacitor voltage converter circuit includes: a switched capacitor converter, a control circuit and a zero current estimation circuit. The switched capacitor converter includes at least one resonant capacitor, switches and at least one inductor. The zero current estimation circuit is coupled to the at least one inductor and/or the at least one resonant capacitor, for estimating a time point at which a first resonant current is zero during a first process and/or a time point at which a second resonant current is zero during a second process according to a voltage difference between two ends of the inductor, and/or a voltage difference between two ends of the resonant capacitor, to a generate a zero current estimation signal accordingly for generating the operation signal.

Adaptive enabling and disabling is described for valley switching in a power factor correction boost converter. In one example, a boost converter control system includes an amplitude detector to receive an amplitude signal from a boost converter that is related to ringing of the boost converter output. The amplitude detector determines the ringing amplitude. A valley switching controller compares the ringing amplitude to a first high amplitude threshold when valley switching is enabled and generates a valley switching disable signal if the ringing amplitude is below the first high amplitude threshold. A cycle controller coupled to the boost converter generates a drive signal to control switching of the boost converter and coupled to the valley switching controller receives the valley switching disable signal to generate the drive signal without valley switching in response to the valley switching disable signal.

A method includes providing a current flowing through a first flying capacitor of a switched-capacitor power converter, measuring a first voltage at one terminal of the first flying capacitor at a first voltage measurement time instant, measuring a second voltage at the one terminal of the first flying capacitor at a second voltage measurement time instant, and calculating a capacitance value of the first flying capacitor based on the first voltage, the second voltage, the first voltage measurement time instant and the second voltage measurement time instant.

Methods, systems, and apparatuses for efficient power supply and voltage division are described. Specifically, the described zero-voltage switching hybrid voltage divider (ZVS-HVD) may implement capacitor-inductor switching (e.g., a capacitor-inductor switching combination) to provide a zero-voltage switching bidirectional voltage divider converter. The ZVD-HVD may be implemented, in the example of a two-to-one ratio divider, via a configuration of three switches, three capacitors, and two small size inductors (e.g., to achieve zero voltage switching in any condition). In some examples, the ZVS-HVD may be realized via two of the switches sharing a same switching signal (e.g., the two-to-one ratio divider example of the described ZVS-HVD may be associated with two circuit states via the three switches). The described ZVS-HVD may support continuous input current, parallelizability, insensitivity to parasitic inductance, and high efficiency (e.g., reduced energy loss) at light load, among other features.

Disclosed is a three-phase interleaved resonant converter, which includes a three-phase inversion circuit connected to an input voltage and including a first output node, a second output node, and a third output node, a three-phase transformer including three transformers, a three-phase resonant circuit including three resonant capacitors and three resonant inductors, and a three-phase rectifier filter circuit. One ends of the three resonant inductors are respectively connected to the first output node, the second output node and the third output node, and the other ends of the three resonant inductors are respectively connected to a triangular configuration formed by an alternate connection of the three resonant capacitors with primary windings of the three transformers. The three-phase rectifier filter circuit is connected with secondary windings of the three transformers to rectify and filter secondary currents output by the secondary windings of the three transformers respectively, and generate an output voltage accordingly.

In an embodiment, a method for operating an ACF converter includes: turning on a low-side transistor that is coupled between a primary winding of a transformer and a reference terminal to cause a forward current to enter the primary winding, turning off the low-side transistor; after turning off the low-side transistor, turning on a high-side transistor that is coupled between the primary winding and a clamp capacitor to cause a reverse current to flow through the primary winding; and after turning on the high-side transistor, when an overcurrent of the reverse current is not detected, keeping the high-side transistor on for a first period of time, and turning off the high-side transistor after the first period of time, and when the overcurrent of the reverse current is detected, turning off the high-side transistor without keeping the high-side transistor on for the first period of time.