Abstract: A snubber circuit for use with, for example, a self-driven synchronous rectifier in a power converter is disclosed. The snubber circuit, in various embodiments, captures and recirculates energy from the leakage inductance of the converter in a substantially lossless manner. The snubber circuit comprises a capacitance for storing the energy accumulated in the leakage inductance of a transformer winding of the converter. The snubber circuit further includes a discontinuous inductor, and a switch for transferring, when on, the energy stored in the capacitance to the inductor. The energy in the inductor may then be discharged when the switch is off.

Abstract: A synchronous rectifier control circuit for controlling a synchronous rectifier of a power converter is disclosed. According to one embodiment, the control circuit includes a differentiator circuit responsive to the output voltage of the power converter. The control circuit also includes a summing circuit responsive to an output of the differentiator circuit and a step function signal. The control circuit further includes an integrator circuit responsive to an output of the summing circuit. In addition, the control circuit includes a gate drive circuit responsive to an output of the integrator circuit and a switching signal that controls a primary switch of the converter. The gate drive circuit also includes an output terminal for coupling to a control terminal of the synchronous rectifier.

Abstract: A housing for a transformer is disclosed. According to one embodiment, the housing includes a top portion, and first, second, third and fourth side portions connected to the top portion. The side portions define an opening. The third side portion includes a first alignment tab and the fourth side portion includes a second alignment tab. The housing also includes first, second, third and fourth termination legs. The first and second termination legs are proximate the third side portion, and the third and fourth termination legs proximate the fourth side portion. A transformer may be disposed in the opening defined by the side portions of the housing.

Abstract: A surface mount power supply device and a method for mounting a lead frame to a circuit board, which has a first and second side, and assembling such a device. The lead frame has leads with a lead solder area for contact with solder material on the circuit board. According to the method, the lead frame and a first set of electrical components are reflow soldered on the first side of the circuit board. Then the circuit board is inverted and a second set of electrical components are reflow soldered on the second surface of the circuit board. The lead solder area and in particular the ratio of the weight of the frame to the lead solder area is chosen so that the lead frame remains connected to the first side of circuit board during the second reflow soldering.

Abstract: A dual input power converter. The dual input power converter includes a transformer, a first primary circuit, and a second primary circuit. The transformer includes a first primary winding and a second primary winding. The first primary circuit is for coupling a first power source to the first primary winding. The second primary circuit is for coupling a second power source to the second primary winding.

Abstract: A drive circuit for a synchronous rectifier of a switch mode power converter is disclosed. The switch mode power converter may include a main power transformer and a primary switch for cyclically coupling the main power transformer to an input source. The drive circuit may comprise a turn-on switch, a turn-off switch, a charge pump and a pulse transformer. The charge pump may be coupled to a secondary winding of the main power transformer. The turn-on switch is for turning on the synchronous rectifier and may be coupled to the charge pump. The pulse transformer may include primary and secondary windings, wherein the primary winding is responsive to a control signal supplied to the primary switch. The turn-off switch is for turning off the synchronous rectifier and may include a control terminal coupled to the secondary winding of the pulse transformer.

Abstract: A surface mount interconnect is disclosed. The interconnect includes a solid conductor having a first section, a second section, and a central section between the first and second sections. The first section includes at least one curved surface, and the second section includes at least one curved surface. The central section includes first and second planar surfaces.

Abstract: A DC-DC power supply with at least two paralleled converters and a current share method for the power supply are presented. According to one embodiment, the power supply includes first and second current mode controlled power converters connected in parallel for powering a load. Each of the paralleled power converters may include a voltage error amplifier, and the output terminals of the respective voltage error amplifiers are connected together. The power supply further includes a slow loop current share control circuit that is responsive to a sensed current in each of the power converters and, based on the sensed currents, forces the power converters to equally contribute to the load current.

Abstract: A DC-DC power converter is presented. According to one embodiment, the converter includes first and second transformers, and a double-ended input circuit, including first and second primary switches, for generating an alternating voltage across the primary windings of the first and second transformers. The converter also includes a control circuit (such as, for example, a PWM control circuit) for controlling the primary switches such that the primary switches are simultaneously OFF for a first time period during a switching cycle of the converter. In addition, the converter includes first and second synchronous rectifiers. The first synchronous rectifier is coupled to the secondary winding of the first transformer and the second synchronous rectifier is coupled to the secondary winding of the second transformer.

Abstract: A toroidal transformer enclosure is disclosed. The toroidal transformer enclosure includes a first housing member and a second housing member structured and arranged to receive the first housing member. The first housing member includes a first end, a first wall and a second wall. The first and second walls are connected to the first end, and the second wall surrounds the first wall. The second housing member includes a second end, a third wall and a fourth wall. The third and fourth walls are connected to the second end, and the fourth wall surrounds the third wall and defines a spacing therebetween. The first and second walls are disposed in the spacing between the third and fourth walls when the first housing member is received by the second housing member.

Abstract: A circuit for providing a regulated voltage to a load. The circuit includes a power converter coupled to the load and including at least one pulse-width modulated switching device, a control circuit for providing a pulse-width modulated control signal to the pulse-width modulated switching device of the power converter based on an output voltage of the power converter, and a transient override circuit responsive to a load voltage for biasing the pulse-width modulated switching device conductive during certain load voltage conditions.

Abstract: A drive circuit for a voltage-controlled switch. The drive circuit includes a normally-on switch including first and second terminals and a control terminal, wherein the first and second terminals have a conduction path therebetween, the second terminal is connected to a conduction control terminal of the voltage-controlled switch, and the control terminal of the normally-on switch is biased by a drive voltage relative to the first terminal of the normally-on switch.

Abstract: A method for assembling a multi-deck power supply device including control and power components. The method comprises providing a first circuit board having a first and a second side. Two prefabricated pin holders are positioned on the first side of the first circuit board. Each pin holder includes two threaded inserts, a set of first pins and a set of second pins. The first pins are floating for self-alignment during soldering. After the first pins are soldered on the first side of the first circuit board, a second circuit board is aligned above the first circuit board, and the first and second pins are soldered to the second circuit board. The first pins may include pre-assembled oscillation dampers, such as magnetic material beads.

Abstract: A dual output power converter, including a transformer having first and second secondary windings, a first synchronous rectifier coupled to the first secondary winding of the transformer for converting an alternating voltage at the first secondary winding to a first DC output voltage, a second synchronous rectifier coupled to the second secondary winding of the transformer for converting an alternating voltage at the second secondary winding to a second DC output voltage, and a drive circuit coupled to each of the first and second synchronous rectifiers for turning on the first and second synchronous rectifiers when the alternating voltage at the first and second secondary windings transition from a first polarity to a second polarity, and for turning off the first and second synchronous rectifiers when the alternating voltage at the first and second secondary windings transition from the second polarity to the first polarity.

Abstract: A DC-to-DC switch-mode power converter. The converter includes a transformer having first and second series-connected primary windings, a first capacitor connected in series to the second primary winding, a first switch for cyclically coupling an input voltage to the first primary winding, a second capacitor, and a second switch for cyclically coupling the first and second primary windings to the second capacitor. The converter may also include a control circuit for alternately driving the first and second switches such that the first and second switches are not simultaneously conductive. The transformer includes at least one secondary winding having a secondary circuit coupled thereto. The secondary circuit may include a rectification circuit employing self-driven synchronous MOSFETs.

Abstract: A DC-DC power converter. According to one embodiment, the power converter includes a symmetrical half-bridge converter including a transformer having a primary winding and first and second secondary windings, a primary circuit coupled to the primary winding, a first rectifier circuit coupled to the first secondary winding, and a second rectifier circuit coupled to the second secondary winding, and first and second buck converters coupled to the half-bridge converter.

Abstract: A power supply, including a regulated switchmode converter, a PWM controller, a semi-regulated converter, and a linear regulator. The regulated switchmode converter is for converting an input voltage to a first output voltage. The PWM controller is responsive to the first output voltage, and includes an output terminal coupled to a control terminal of a switch of the regulated switchmode converter. The semi-regulated switchmode converter is for converting the input voltage to an intermediate output voltage, and includes a switch having a control terminal coupled to the output terminal of the PWM controller. The linear regulator is coupled to the semi-regulated switchmode converter and is for converting the intermediate output voltage to a second output voltage.

Abstract: An electrical device. The electrical device includes a first substrate, a second substrate facing the first substrate, a unpackaged semiconductor die electrically and thermally connected to the first substrate, a first lead electrically connected between the unpackaged semiconductor die and the second substrate, and a second lead electrically connected between the first and second substrates.

Abstract: A method and apparatus for dissipating heat from an electrical component. The method includes providing a planar element including a first electrically and thermally conductive region and a second electrically and thermally conductive region, such that the first and second regions define a spacing therebetween, and wherein the planar element includes at least one mechanically stabilizing tie connected between the first and second regions across the spacing, directly connecting a first terminal of an electrical component to the first region, directly connecting a second terminal of the electrical component to the second regions, such that the electrical component bridges the spacing, and removing the at least one mechanically stabilizing tie from between the first and second regions.

Abstract: A power factor correction circuit for a boost power supply, wherein the boost power supply includes a boost converter responsive to a rectified AC line voltage. According to one embodiment, the power factor correction circuit includes a voltage feedback amplifier having a first input terminal responsive to an output voltage of the boost converter, a switching multiplier circuit having a first input terminal connected to an output terminal of the voltage feedback amplifier and a second input terminal responsive to the rectified AC line voltage, a current feedback amplifier having a first input terminal connected to an output terminal of the switching multiplier circuit and having a second input terminal responsive to an input current of the boost converter, and a pulse width modulator control circuit having an input terminal connected to an output terminal of the current feedback amplifier and having an output terminal for connection to a pulse width modulated switch of the boost converter.