An interleaved LLC converter arrangement includes two or more LLC converters for transferring power from an input side to an output side, wherein the two or more LLC converters include a first LLC converter and a second LLC converter connected in parallel on the input side and on the output side and wherein each LLC converter includes a bridge inverter at the input side. For balancing the power transfer among the LLC converters if for example the second LLC converter transfers more power from the input side to the output side than the first LLC converter, each leg of the bridge of the bridge inverter of the first LLC converter is operated with a duty cycle of 0.5 and at least one leg of the bridge of the bridge inverter of the second LLC converter is operated with a duty cycle different from 0.5.

Disclosed herein is a control circuit of an isolated power supply including a first transformer and a primary-side transistor connected to a primary winding of the first transformer. The control circuit includes a timing generator that generates a timing signal with reference to an edge of a switching signal generated on a secondary side of the isolated power supply, a sampling circuit that, in response to the timing signal, samples an electric signal to be monitored, the electric signal to be monitored being an electric signal on the secondary side of the isolated power supply, and a feedback controller that, based on an output of the sampling circuit, generates a primary-side pulse signal to be supplied to the primary-side transistor.

A DC-DC converter has a configuration in which a first full-bridge circuit and a second full-bridge circuit are connected via a transformer and an inductor. A control circuit controls soft switching of each switching element in the first full-bridge circuit and the second full-bridge circuit. An inductor current flowing through an equivalent inductor at a time of switching of turning on or off each switching element is greater than or equal to a threshold current, the equivalent inductor being equivalent to the transformer and the inductor. The control circuit outputs predetermined power by changing a voltage output period of the first full-bridge circuit and a voltage output period of the second full-bridge circuit while fixing the switching frequency and keeping constant a polarity inversion period in which the output of the second full-bridge circuit and the output of the first full-bridge circuit have reverse polarities. This enables performing ZVS operations by simple control and reducing switching losses.

A resonant power converter controller comprising a control circuit configured to turn on a synchronous rectifier (SR) in response to a count of a number of times a drain voltage of the SR crosses below a turn on threshold based on a stored count and turns off the SR when the drain voltage crosses above a turn off threshold. The control circuit comprises a first comparator configured to generate a first detection signal in response to the drain voltage being less than the turn on threshold. A first turn on detection circuit generates a first turn on signal when the count reaches the stored count. A first turn off signal is generated in response to the drain voltage being greater than the turn off threshold. A drive circuit turns on and off the SR in response to the first turn on signal and the first turn off signal.

An isolated converter with high boost ration includes a transformer, a first bridge arm, a second bridge arm, and a boost circuit. The transformer includes a secondary side having a secondary side first node and a secondary side second node. The first bridge arm includes a first diode and a second diode. The second bridge arm includes a third diode and a fourth diode. The boost circuit includes at least one fifth diode coupled between the first bridge arm and the secondary side second node, at least one sixth diode coupled between the second bridge arm and the secondary side first node, and at least two capacitors coupled to the secondary side first node and the secondary side second node.

Switching power supply apparatus having standby mode in which a burst operation is performed. High- and low-side switching elements are series connected across a DC input voltage. A resonant circuit is connected across one of the switching elements. A controller that on-off controls the high-side switching element includes a peak power limiting circuit that monitors input power and outputs a forced turn-off signal upon detecting input power exceeding a determined value. A triangular wave voltage is generated during portions of the burst operation in which a switching frequency of the switching elements is gradually decreased or increased. An oscillation circuit receives the forced turn-off signal from the power limiting circuit, and the triangular wave voltage to generate an on-trigger and off-trigger signals at a switching frequency corresponding to a triangular wave voltage value, and output the off-trigger signal upon receipt of the forced turn-off signal.

A system and method of determining a value of a feedback parameter of a feedback loop of a power converter. In one embodiment, the method includes shifting an open-loop performance characteristic and a closed-loop performance characteristic of the feedback loop so that values thereof are greater than or equal to respective constants. The method also includes normalizing the open-loop performance characteristic and the closed-loop performance characteristic to a common scale to provide a normalized open-loop performance characteristic and a normalized closed-loop performance characteristic. The method also includes combining the normalized open-loop performance characteristic with the normalized closed-loop performance characteristic to provide a combined normalized performance characteristic. The method also includes finding a value of the feedback parameter that produces an extremum of the combined normalized performance characteristic.

A controller includes a first sensing pin receiving a first sensing signal indicating a level of an input voltage of a resonant converter, a second sensing pin receiving a second sensing signal indicating a level of an input current of the resonant converter, a feedback pin receiving a feedback signal indicating a level of an output voltage of the resonant converter, and a first driving pin and a second driving pin controlling a high side switch and a low side switch of the resonant converter, respectively. The controller generates a compensated signal based on the first sensing signal, compares the compensated signal with a peak value of the second sensing signal to generate a first comparison result, compares the feedback signal with a threshold to generate a second comparison result, and controls the high side low side switches based on the first and the second comparison results.

A compensating method for a ripple compensation circuit of a power supply is provided. The power supply includes an LLC resonant converter. The LLC resonant converter receives an input voltage and generates an output voltage. Firstly, the output voltage is subtracted from a reference voltage, so that a first error signal is generated. Then, a digital filter is provided to increase a low frequency gain of the first error signal, so that a second error signal is generated. Then, the first error signal and the second signal are added, so that a modulated error signal is generated. Then, a compensation signal is generated to control the LLC resonant converter according to the modulated error signal. Consequently, a low frequency gain of the input voltage is increased and a low frequency ripple of the output voltage is suppressed by an increased voltage loop compensator response.

A power converter apparatus employs an energy recovery auxiliary circuit to suppress overvoltage oscillations and achieve high efficiency in a resonant LLC power converter system having high power density. The power converter apparatus includes an inverter configured to receive a DC input power and produce an AC voltage, a resonant tank including a resonant inductor and a resonant capacitor coupled between the AC voltage and a primary winding of a transformer, a rectifier configured to produce a DC output power coupled to a secondary winding of the transformer. The power converter suppresses overvoltage oscillations on rectifier switches by employing an energy recovery auxiliary circuit to transfer, during a transition period, current from the secondary side to a clamping capacitor conductively coupled to the primary side of the converter. The energy is then recovered during a subsequent power transfer cycle, thereby improving overall efficiency of the power converter.