Abstract: An energy transfer element comprises a U-shaped core of powder core, the U-shaped core having two legs and a gap in a magnetic path, a bar comprising magnetizable material positioned in the gap such that the magnetic core and magnetizable material form a rectangular toroid, and one or more power windings wrapped around the magnetic path. The magnetizable material is capable of being magnetized. When the magnetizable material is unmagnetized, the magnetizable material has an initial flux density. When the magnetizable material is magnetized, the flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material is an unmagnetized magnet or a suspension medium such as epoxy with magnetized magnetizable particles and powder core. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: A method for making an energy transfer element provides a magnetic core having a gap in a magnetic path, positions in the gap magnetizable material that produces an initial flux density, cures the suspension medium, and wraps one or more power windings around the magnetic path. When the magnetizable material is magnetized, a flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material comprises a mixture of a suspension medium that includes uncured epoxy and magnetizable particles. The magnetizable particles are capable of permanent magnetic properties when magnetized. The particles of magnetic material having magnetic permeability of at least 1000?o. The particles of magnetic material that have a magnetic permeability of at least 1000?o and the particles of magnetizable particles are uniformly distributed in the suspension medium.

Abstract: An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

Abstract: A method of forming one or more contact regions in a high-voltage field effect transistor (HFET) includes providing a semiconductor material, including a first active layer and a second active layer, with a gate dielectric disposed on a surface of the semiconductor material. A first contact to the semiconductor material is formed that extends through the second active layer into the first active layer, and a passivation layer is deposited, where the gate dielectric is disposed between the passivation layer and the second active layer. An interconnect is formed extending through the first passivation layer and coupled to the first contact. An interlayer dielectric is deposited proximate to the interconnect, and a plug is formed extending into the interlayer dielectric and coupled to the first portion of the interconnect.

Abstract: A controller for a power converter comprising a drive signal generator and drive strength control and a variable strength multi-stage gate driver. The drive signal generator and drive strength control outputs a drive signal to control switching of a power switch and a strength signal to control drive strength of the power switch. The variable strength multi-stage gate driver is configured to turn ON the power switch in response to the drive signal with a first drive strength then a second drive strength when the strength signal is not asserted. The variable strength multi-stage gate driver is configured to turn ON the power switch in response to the drive signal with a third drive strength then the second drive strength when the strength signal is asserted. The second drive strength is stronger than the first drive strength and the first drive strength is stronger than the third drive strength.

Abstract: Pulse sharing control to enhance performance in multiple output power converters is described herein. During a switching cycle, an energy pulse is provided to more than one port (i.e., output) using pulse sharing transfer. Pulse sharing transfer may enhance performance by reducing audible noise due to subharmonics and by reducing a root mean square current of one or more secondary currents. A primary switch is closed to energize an energy transfer element via a primary current. Energy may be shared among a first load port on a first circuit path via a first secondary current and among a second load port on a second circuit path via a second secondary current.

Abstract: An inductive charging circuit coupled to a winding of a power converter and a supply terminal of a controller of the power converter. The inductive charging circuit comprising an input coupled to the winding, the input coupled to receive a switching voltage generated by the power converter, an inductor coupled to the input to provide an inductor current in response to the switching voltage, a first diode coupled to the inductor to enable the inductor current to flow from the input of the inductive charging circuit to an output of the inductive charging circuit; and the output of the inductive charging circuit coupled to the supply terminal of the controller, the output of the inductive charging circuit configured to provide an operational current responsive to the switching voltage, the controller is configured to control a power switch of the power converter to generate the switching voltage.

Abstract: An HFET includes a first and second semiconductor material. A first composite passivation layer includes a first insulation layer and a first passivation layer, and the first passivation layer is disposed between the first insulation layer and the second semiconductor material. The HFET includes a second passivation layer, where the first insulation layer is disposed between the first passivation layer and the second passivation layer. A gate dielectric is disposed between the second semiconductor material and the first passivation layer. A source electrode and a drain electrode are coupled to the second semiconductor material, and a gate electrode is disposed laterally between the source electrode and the drain electrode. A first gate field plate is disposed between the first passivation layer and the second passivation layer and electrically connected to the gate electrode, and a second gate field plate is disposed above first gate field plate.

Abstract: Apparatus and methods for controllable networks to vary inter-stage power transfer in a multi-stage power conversion system are disclosed herein. By using controllable networks (111-113) within the first power converter stage (102), intermediate power delivered to a subsequent or second power converter stage (104) can be varied so that the multi-stage power conversion system (100) may respond to a full load step while offering improved light load power conversion efficiency. A power estimation circuit (122) within the second power converter stage (104) can provide a control signal (Cl-CN) to each of the controllable networks (111-113); the controllable networks (111-113), in turn, can provide network signals (SI, S2) to control the intermediate power delivered to the second power converter stage (104).

Abstract: A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor module is coupled to generate a clock signal in response to the measured signal characteristic stored in the memory. The switch drive signal is coupled to be generated in response to the clock signal during the second mode.

Abstract: A controller comprising a regulation circuit and a frequency request circuit. The regulation circuit configured to receive a signal representative of an output and a reference representative of a desired value of the output, the regulation circuit configured to output a regulation signal in response to a difference between the signal and the reference. The frequency request circuit configured to receive the regulation signal and outputs an increment signal representative of a request to increase a switching frequency and a decrement signal representative of a request to decrease the switching frequency in response to the regulation signal. The frequency request circuit configured to assert the increment signal when the output is less than the desired value for a duration longer than a first period and assert the decrement signal when the output is greater than the desired value for a duration longer than a second period.

Abstract: An inductive charging circuit coupled to a winding of a power converter and a supply terminal of a controller of the power converter. The inductive charging circuit comprising an input coupled to the winding, the input coupled to receive a switching voltage generated by the power converter, an inductor coupled to the input to provide an inductor current in response to the switching voltage, a first diode coupled to the inductor to enable the inductor current to flow from the input of the inductive charging circuit to an output of the inductive charging circuit; and the output of the inductive charging circuit coupled to the supply terminal of the controller, the output of the inductive charging circuit configured to provide an operational current responsive to the inductor current to the controller, the controller is configured to control a power switch of the power converter to generate the switching voltage.

Abstract: A secondary controller for use in a power converter includes a drive circuit coupled to a secondary side of the power converter. The drive circuit is coupled to generate a first signal to enable a first switch coupled to a primary side of the primary converter. The first signal is generated in response to a feedback signal representative of an output of the power converter. A control circuit is coupled to receive the first signal and an input signal representative of a secondary winding voltage of the power converter. The control circuit is coupled to generate a second signal to control a second switch coupled to the secondary side of the power converter in response to the first signal and the input signal.

Abstract: A superjunction device comprising a drain contact, a substrate layer above the drain contact, an epitaxial layer above the substrate layer, a P+ layer above the epitaxial layer formed by P-type implantation to a bottom of the superjunction device, a trench with a sloped angle formed by use of a hard mask layer. The trench is filled with an insulating material. A first vertical column is formed adjacent to the trench. A second vertical column is formed adjacent to the first vertical column. A source contact is coupled to the first vertical column and the second vertical column. A P-body region is coupled to the source contact. A gate oxide is formed above the source contact and the epitaxial layer, and a gate formed above the gate oxide.

Abstract: A method of providing an input switching request signal to an input side switch includes determining a switching request window indicative of relaxation ringing during a first switching cycle. It is determined that the input side switch is operating in a discontinuous conduction mode (DCM) mode of operation during a second switching cycle. It is determined that the switching request window is open during the second switching cycle. The input switching request signal is enabled in response to determining the switching request window is open.

Abstract: A power converter comprising an energy transfer element is coupled between an input of the power converter and an output of the power converter. A cascode circuit generates a first sense signal and a second sense signal. A controller controls the switching of the cascode circuit to transfer energy from the input of the power converter to the output of the power converter. The controller comprising a current sense circuit generates a current limit signal and an overcurrent signal in response to the first sense signal and the second sense signal. A control circuit generates a control signal in response to the current limit signal and the overcurrent signal. A drive circuit comprising a first stage gate drive circuit generates a drive signal in response to the control signal to reduce EMI, and a second stage of gate drive circuit to enable accurate current sensing of the cascode circuit.

Abstract: An auxiliary converter coupled to an output of a main power converter comprising an auxiliary switch, a timing circuit, and an energy transfer element. The auxiliary switch coupled to the output of the main power converter. A timing circuit coupled to receive a control signal from a controller of the main power converter, wherein the controller regulates the output of the main power converter, the timing circuit configured to output an auxiliary drive signal to control switching of the auxiliary switch in response to the control signal. The energy transfer element coupled to the auxiliary switch, wherein the energy transfer element is configured to transfer energy from the output of the main power converter to a supply of the controller, the supply provides operational power for the controller of the main power converter.

Abstract: A primary controller configured for use in a power converter comprising a control circuit configured to determine a mode of operation of the power converter in response to a drive signal of a power switch. The control circuit further configured to generate a control signal in response to a signal representative of the mode of operation of the power converter, wherein the control signal represents a delay time to enable a turn on of the power switch after a turn off of a clamp switch. The control circuit further configured to generate a clamp drive signal to control the clamp switch. The primary controller further comprises a drive circuit configured to generate a drive signal to enable the power switch to transfer energy from an input of the power converter to an output of the power converter.

Abstract: A controller for use in a power converter includes a secondary controller coupled to receive a feedback signal representative of an output of the power converter to generate d a request signal. A primary controller is coupled to receive the request signal to generate a primary drive signal. The primary drive signal is coupled to control switching of a power switch to control a transfer of energy from the input to the output of the power converter. A frequency to on-time converter included in the primary controller is coupled to receive the request signal. The frequency to on-time converter is coupled to control the duration of on-time pulses included in the primary drive signal in response to a period of the request signal.

Abstract: A controller for use in a power converter for transferring energy between an input and an output, the controller comprising a second controller to generate a request event and a request signal in response to a feedback signal and a switching window signal, the second controller to transmit the request event during a switching window of the switching window signal. The second controller comprising an extremum locator switching window generator to generate the switching window corresponding with an extremum in the winding signal and a measurement enable circuit to output an enable signal to enable the extremum locator switching window generator to measure a duration of a half cycle to generate the switching window. The measurement enable circuit to enable the extremum locator switching window generator in response to the feedback signal reaching a percentage of a target reference and output a quiet signal to prevent transmitting the request event.