Abstract: A power converter comprises a transformer having a primary winding and a secondary winding, a first switch coupled with the secondary winding, a filter circuit coupled with the first switch and comprising a resistor-capacitor (RC) filter coupled in series with a second switch, and a switch controller. The switch controller is coupled with the first switch and the filter circuit and configured to sense a voltage across the first switch, compare the voltage across the first switch with a voltage threshold, and control a gate of the first switch and a gate of the second switch in response to the comparison of the voltage.

Abstract: A flyback voltage converter comprising an inductive winding, a main switch coupled in series with the inductive winding via a common node, and a snubber circuit coupled in parallel with the inductive winding and comprising a controllable switch having a gate and a source, wherein the gate is coupled with the source to prevent the controllable switch from turning on. A control circuit is coupled with the main switch and configured to turn the main switch on and off to convert an input voltage to an output voltage distinct from the input voltage.

Abstract: A voltage converter comprising a voltage input, a transformer comprising a primary winding coupled with the voltage input, a main switch coupled at a node with the primary winding, a snubber circuit coupled with the voltage input and with the node, the snubber circuit comprising a controllable switch having a gate and a source. A control circuit is coupled with the main switch and configured to turn the main switch on and off to convert an input voltage supplied to the voltage input to an output voltage distinct from the input voltage. The gate is coupled with the source to prevent the controllable switch from turning on.

Abstract: A voltage converter comprising a voltage input, a transformer comprising a primary winding coupled with the voltage input, a main switch coupled at a node with the primary winding, a snubber circuit coupled with the voltage input and with the node, the snubber circuit comprising a controllable switch having a gate and a source. A control circuit is coupled with the main switch and configured to turn the main switch on and off to convert an input voltage supplied to the voltage input to an output voltage distinct from the input voltage. The gate is coupled with the source to prevent the controllable switch from turning on.

Abstract: A transformer for a multiphase power converter includes a magnetic structure, a first coil configured to electrically couple to an input circuit or an output circuit of a subconverter of the multiphase power converter, and a second coil configured to electrically couple to an input circuit or an output circuit of another subconverter of the multiphase power converter. The magnetic structure includes a top member, a bottom member, and legs extending between the top member and the bottom member in substantially the same direction. The legs include two outer members and two inner members. The first coil is wound about one of the two inner members of the magnetic structure, and the second coil is wound about the other one of the two inner members of the magnetic structure. Other example transformers, and multiphase power converters including transformers are also disclosed.

Abstract: An AC/DC power converter includes input terminals, output terminals, a power factor correction circuit coupled between the input and output terminals and including at least one power switch defining a switched current path, and a current transformer including a primary winding and a secondary winding. The primary winding is coupled in series with the switched current path. The power converter also includes a first sense switch coupled with a first end of the secondary winding, a second sense switch coupled with a second end of the secondary winding, and a control circuit. The control circuit is configured to turn on the first sense switch and turn off the second sense switch during a positive polarity of the AC voltage input, and to turn off the first sense switch and turn on the second sense switch during a negative polarity of the AC voltage input.

Abstract: An AC/DC power converter includes input terminals, output terminals, a power factor correction circuit coupled between the input and output terminals and including at least one power switch defining a switched current path, and a current transformer including a primary winding and a secondary winding. The primary winding is coupled in series with the switched current path. The power converter also includes a first sense switch coupled with a first end of the secondary winding, a second sense switch coupled with a second end of the secondary winding, and a control circuit. The control circuit is configured to turn on the first sense switch and turn off the second sense switch during a positive polarity of the AC voltage input, and to turn off the first sense switch and turn on the second sense switch during a negative polarity of the AC voltage input.

Abstract: A transformer for a multiphase power converter includes a magnetic structure, a first coil configured to electrically couple to an input circuit or an output circuit of a subconverter of the multiphase power converter, and a second coil configured to electrically couple to an input circuit or an output circuit of another subconverter of the multiphase power converter. The magnetic structure includes a top member, a bottom member, and legs extending between the top member and the bottom member in substantially the same direction. The legs include two outer members and two inner members. The first coil is wound about one of the two inner members of the magnetic structure, and the second coil is wound about the other one of the two inner members of the magnetic structure. Other example transformers, and multiphase power converters including transformers are also disclosed.

Abstract: An AC/DC power converter includes input terminals, output terminals, a power factor correction circuit coupled between the input and output terminals and including at least one power switch defining a switched current path, and a current transformer including a primary winding and a secondary winding. The primary winding is coupled in series with the switched current path. The power converter also includes a first sense switch coupled with a first end of the secondary winding, a second sense switch coupled with a second end of the secondary winding, and a control circuit. The control circuit is configured to turn on the first sense switch and turn off the second sense switch during a positive polarity of the AC voltage input, and to turn off the first sense switch and turn on the second sense switch during a negative polarity of the AC voltage input.

Abstract: Methods of making an assembly are disclosed. The assembly may include a circuit board with a top surface and a circuit component mounted on the top surface of the circuit board. The method may include positioning an inductor coil above the circuit component and the top surface of the circuit board and encapsulating the inductor coil, the circuit component and at least part of the top surface of the circuit board in a magnetic material. Assemblies according to such methods are also disclosed.

Abstract: A method of controlling an isolated switching power converter that includes a transformer with a primary side and a secondary side, at least one primary switch coupled to the primary side of the transformer and at least one synchronous rectifier coupled to the secondary side of the transformer is disclosed. The method includes turning on the synchronous rectifier a first fixed time after turning on the primary switch and turning off the synchronous rectifier a second fixed time after turning off the primary switch. Power converters for operation according to this method are also disclosed, including power converters without an output inductor.

Abstract: Methods of making an assembly are disclosed. The assembly may include a circuit board with a top surface and a circuit component mounted on the top surface of the circuit board. The method may include positioning an inductor coil above the circuit component and the top surface of the circuit board and encapsulating the inductor coil, the circuit component and at least part of the top surface of the circuit board in a magnetic material. Assemblies according to such methods are also disclosed.

Abstract: A method of controlling an isolated switching power converter that includes a transformer with a primary side and a secondary side, at least one primary switch coupled to the primary side of the transformer and at least one synchronous rectifier coupled to the secondary side of the transformer is disclosed. The method includes turning on the synchronous rectifier a first fixed time after turning on the primary switch and turning off the synchronous rectifier a second fixed time after turning off the primary switch. Power converters for operation according to this method are also disclosed, including power converters without an output inductor.

Abstract: A power converter that includes a transformer, a bridge input circuit, a self-driven synchronous rectifier circuit, a gate drive circuit, and a gate drive shutdown circuit. The transformer includes a primary winding connected to the bridge input circuit, a first secondary winding, and a second secondary winding. The self-driven synchronous rectifier circuit is connected to the first secondary winding and includes a first synchronous rectifier for rectifying a voltage across the first secondary winding. The first synchronous rectifier includes a control terminal responsive to a voltage across the second secondary winding. The gate drive circuit includes a first diode connected to the control terminal of the first synchronous rectifier for introducing a dc level shift thereto.

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.