Abstract: An apparatus includes an isolated power converter having an input connected to an input dc power source, a first output and a second output, and a non-isolated power converter having an input connected to the second output of the isolated power converter, wherein the first output of the isolated power converter and an output of the non-isolated power converter are connected in series.

Abstract: An apparatus includes an isolated power converter having an input connected to an input dc power source, a first output and a second output, and a non-isolated power converter having an input connected to the second output of the isolated power converter, wherein the first output of the isolated power converter and an output of the non-isolated power converter are connected in series.

Abstract: A method includes generating a first ramp signal for controlling a first portion of a converter, generating a second ramp signal for controlling a second portion of the converter, controlling a state of a first switch of the first portion through comparing the first ramp signal to a control signal and a state of a first switch of the second portion through comparing the second ramp signal to the control signal and determining a switching cycle of the converter through comparing a current flowing through an inductor of the converter to a threshold.

Abstract: An apparatus comprises an isolated power converter coupled to an input dc power source, wherein the isolated power converter comprises a first switch network coupled to a first transformer winding and a second switch network coupled to a second transformer winding and a non-isolated power converter coupled to the second switch network of the isolated power converter, wherein a current flowing through the non-isolated power converter is a fraction of a current flowing through the isolated power converter.

Abstract: A device comprises a gate drive bridge coupled between a bias voltage of a power converter and ground and a transformer connected to the gate drive bridge, wherein the transformer comprises a primary winding connected to two legs of the gate drive bridge respectively and a plurality of secondary windings configured to generate gate drive signals for low side switches, high side switches and secondary switches of the power converter.

Abstract: A system comprises an input power stage coupled to a primary side of a transformer, an output power stage coupled to a secondary side of a transformer, a first common node capacitor and a common node resistor connected in series between a midpoint of the secondary side of the transformer and ground and a detector having an input connected to a common node of the first common node capacitor and the common node resistor, and an output connected to a control circuit, wherein the control circuit is configured to dynamically adjust a switching frequency of the system based upon an output of the detector.

Abstract: A method includes generating a first ramp signal for controlling a first portion of a converter, generating a second ramp signal for controlling a second portion of the converter, controlling a state of a first switch of the first portion through comparing the first ramp signal to a control signal and a state of a first switch of the second portion through comparing the second ramp signal to the control signal and determining a switching cycle of the converter through comparing a current flowing through an inductor of the converter to a threshold.

Abstract: A system comprises an input power stage coupled to a primary side of a transformer, an output power stage coupled to a secondary side of a transformer, a first common node capacitor and a common node resistor connected in series between a midpoint of the secondary side of the transformer and ground and a detector having an input connected to a common node of the first common node capacitor and the common node resistor, and an output connected to a control circuit, wherein the control circuit is configured to dynamically adjust a switching frequency of the system based upon an output of the detector.

Abstract: A method comprises generating a first ramp signal and a second ramp signal for controlling a buck converter portion and a boost converter portion of a buck-boost converter respectively, comparing the first ramp signal and the second ramp signal to a control signal, controlling the buck converter portion using the comparing the first ramp signal to the control signal and the boost converter portion using the comparing the second ramp signal to the control signal, comparing a current flowing through the inductor to a current threshold and terminating a switching cycle based upon the comparing the current flowing through the inductor to the current threshold.

Abstract: A method comprises connecting a first resonant converter and a second resonant converter in parallel, detecting a first signal indicating a first soft switching process of the first resonant converter and a second signal indicating a second soft switching process of the second resonant converter and adjusting a first switching frequency of the first resonant converter by a first control circuit and a second switching frequency of the second resonant converter by a second control circuit until a load current flowing through the first resonant converter is substantially equal to a load current flowing through the second resonant converter.

Abstract: A device comprises a gate drive bridge coupled between a bias voltage of a power converter and ground and a transformer connected to the gate drive bridge, wherein the transformer comprises a primary winding connected to two legs of the gate drive bridge respectively and a plurality of secondary windings configured to generate gate drive signals for low side switches, high side switches and secondary switches of the power converter.

Abstract: A method comprises providing a resonant converter comprising a switching network comprising a first high-side switch, a second high-side switch, a first low-side switch and a second low-side switch, a resonant tank coupled between the switching network and a transformer and a rectifier coupled to a secondary side of the transformer, coupling a driver to the switching network and the rectifier, wherein the driver includes a first winding coupled to the rectifier, a second winding coupled to the first high-side switch and a third winding coupled to the second high-side switch, detecting a signal indicating a soft switching process of the driver and adjusting a resonant frequency of the driver until the resonant frequency of the driver approximately matches a switch frequency of the resonant converter.

Abstract: A method comprises determining an operating mode based upon an input voltage and an output voltage of a resonant converter, wherein the resonant converter comprises a switch network coupled to an input dc power source, a resonant tank coupled to the switch network and a transformer coupled between the resonant tank and a secondary rectifier, wherein the secondary rectifier is a full-bridge rectifier, configuring the switch network to operate at a buck converter mode in response to a first input voltage and configuring the secondary rectifier to operate at a boost converter mode in response to a second input voltage, wherein the first voltage is higher than the output voltage and the second voltage is lower than the output voltage.

Abstract: A converter comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a magnetic device coupled to the switch network, a detector coupled to the magnetic device through a magnetic coupling and a control circuit configured to receive a zero voltage switching signal from the detector and adjust gate drive signals of the power switches based upon the zero voltage switching signal.

Abstract: A method comprises providing a buck-boost converter comprising a first high-side switch and a first low-side switch connected in series across an input capacitor, a second high-side switch and a second low-side switch connected in series across an output capacitor and an inductor coupled between a common node of the first high-side switch and the first low-side switch, and a common node of the second high-side switch and the second low-side switch, detecting a first voltage resonance waveform across a switch of the buck-boost converter and turning on the switch of the buck-boost converter when the first voltage resonance waveform falls to zero.

Abstract: A method comprises detecting a signal representing a drain-to-source voltage of a switch of a synchronous rectifier of an inductor-inductor-capacitor (LLC) resonant converter, comparing the signal with a predetermined threshold, generating a first logic state if the drain-to-source voltage is greater than the predetermined threshold, generating a second logic state if the drain-to-source voltage is less than the predetermined threshold and in response to the first logic state and the second logic state, adjusting a switching frequency of the LLC resonant converter such that the switching frequency moves back and forth across a boundary of body diode conduction, wherein a frequency difference between the switching frequency and a resonant frequency of the LLC resonant converter is less than or equal to one frequency adjustment step.

Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a first resonant tank coupled to the input stage, wherein the first resonant tank is of a first Q value, a second resonant tank coupled to the input stage, wherein the second resonant tank is of a second Q value, a transformer coupled to the input stage through the first resonant tank and the second resonant tank and an output stage coupled to the transformer.

Abstract: An apparatus comprises an isolated power converter coupled to an input dc power source, wherein the isolated power converter comprises a first switch network coupled to a first transformer winding and a second switch network coupled to a second transformer winding and a non-isolated power converter coupled to the second switch network of the isolated power converter, wherein a current flowing through the non-isolated power converter is a fraction of a current flowing through the isolated power converter.

Abstract: A method for improving a power converter's efficiency comprises detecting an input voltage of a power converter, determining an operation mode of the power converter based upon the input voltage of the power converter and generating a plurality of gate drive signals based upon a damped gain control, wherein the damped gain control is configured such that an output voltage of the power converter is in a range from a tightly regulated output voltage to an unregulated output voltage.

Abstract: An apparatus comprises an isolated power converter coupled between an input dc power source, wherein the isolated power converter comprises a first switch network coupled to a first transformer winding through a first resonant tank and a second switch network coupled to a second transformer winding through a second resonant tank and a dc/dc converter coupled to the second switch network.