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.

Circuits that provide an auxiliary power supply on the secondary side of an isolated switched-mode power converter are described. Such an auxiliary supply may be used to provide power to a secondary side controller or to other circuitry in the secondary side of the power converter. During at least a start-up phase of the power converter, the secondary side auxiliary power supply is supplied power by use of a self-starting primary side driver that operates autonomously until the secondary side controller is fully operational. Circuits and methods for such a self-starting primary side driver are provided. The techniques disclosed provide for a secondary side auxiliary power supply that uses minimal additional circuitry.

An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a primary power circuit and a secondary power circuit. The primary power circuit receives an alternating current (AC) input power signal from an electrical power source and generates an intermediate direct current (DC) power signal. The intermediate DC power signal is generated at a first voltage level that is less than a voltage level of the AC input power signal. The secondary power circuit receives the intermediate DC power signal from the primary power circuit and delivers an output DC power signal to an electronic device. The output DC power signal is delivered at an output voltage level that is less than the first voltage level of the intermediate DC power signal.

A discharge circuit has a voltage divider arranged to divide an alternating-current input voltage to produce a divided voltage, a high-pass filter arranged to pass a high-frequency component of the divided voltage to produce a monitoring voltage, a comparator arranged to compare the monitoring voltage with a threshold voltage to produce a comparison signal, a timer arranged to generate a timer signal indicating whether or not the comparison signal has been kept at the same logic level for a mask period, a controller arranged to generate a discharge control signal according to the timer signal, and a discharger arranged to discharge, according to the discharge control signal, an X capacitor connected to a node to which the alternating-current input voltage is applied.

According to at least one aspect, embodiments herein provide an adaptive battery pack module comprising a Li-ion battery, a low-voltage bus coupled to the Li-ion battery, a bi-directional DC-DC converter coupled to the low-voltage bus, a low-voltage output coupled to the low-voltage bus, a high-voltage output, and a high-voltage bus coupled between the bi-directional DC-DC converter and the high-voltage output, wherein the low-voltage output is configured to be coupled to at least one Li-ion battery of at least one external battery pack module, and wherein the bi-directional DC-DC converter is configured to receive DC power from the Li-ion battery and the at least one Li-ion battery of the at least one external battery pack module via the low-voltage bus, convert the received DC power into output DC power, and provide the output DC power to the high-voltage bus.

A circuit for providing dynamic output current sharing using average current mode control for active-reset and self-driven synchronous rectification with pre-bias startup and redundancy capabilities for power converters. The circuit communicates a secondary side feedback signal to a primary side via a bidirectional magnetic communicator that also provides a secondary voltage supply. Pre-bias startup is achieved by detection of the output current direction and controlling the gate signals of synchronous rectifiers. The circuit permits dynamic current sharing via a single-control signal and automatic master converter selection and promotion.

A system architecture for a battery charger that employs GaN-based power devices. The system takes advantage of the active power electronics circuits for power conversion, utilizing controls for power factor correction at its input and constant current/constant voltage regulation at its output. Specifically, a universal GaN-based battery charger architecture is proposed for charging either low- or high-voltage batteries using either three-phase 230-V variable frequency or three-phase 115-V constant frequency AC input power, while meeting stringent power quality and electromagnetic interference aerospace requirements.

A power system includes DC-DC power conversion circuitry that has a first switch and a second switch on either side of a transformer, and the second switch is operates as a synchronous rectifier. Power transfer from a primary side to secondary side of the DC-DC power conversion circuitry is controlled by operating the first switch. A drive signal for the second switch is calculated based on a sensed transformer winding current, and operation of the second switch is controlled based on the drive signal.

A switching power supply apparatus includes a first series circuit including a third rectifier device and a fourth rectifier device and that is connected between a positive output terminal and a negative output terminal, and a first capacitor a first end of which is connected to a connection node between the third rectifier device and the fourth rectifier device and a second end of which is connected to an end, not connected to the first series circuit, of a first rectifier device or a second rectifier device. The first series circuit and the first capacitor define a snubber circuit.

One example embodiment is a method executed by a microcontroller with a Pulse Width Modulation (PWM) circuit to control a semi-dual-active-bridge (SDAB) converter that includes a first side bridge circuit, a second side bridge circuit and a transformer. The microcontroller determines a current operation mode and a target operation mode of the SDAB converter. The microcontroller determines an optimal ratio and calculates changes of each gating signal that are applied to the first side bridge circuit and the second side bridge circuit respectively.