Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of dielectric regions disposed in the semiconductor layer. The dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Each dielectric region has a rounded-square cross-section in a horizontal plane perpendicular to the vertical direction. Adjacent ones of the dielectric regions are laterally separated by a narrow region of the semiconductor layer. Each dielectric region has a cylindrical field plate member centrally disposed therein. The cylindrical field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrical field plate member from the narrow region. A source region is disposed at the top surface, and a drain region is disposed at the bottom, of the semiconductor layer.

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 configured for use with a power converter and a power switch comprising a primary controller coupled to the power converter and configured to provide a switch drive signal to control switching of the power switch to transfer energy from a primary side to a secondary side of the power converter. A primary switching pattern circuit is configured to provide a primary switching pattern to operate the primary controller in a first mode of operation and a primary switch control circuit is coupled to the primary switching pattern circuit and configured to receive a control signal representative of turn-on of the power switch, to receive the primary switching pattern, and to output the switch drive signal. The primary switch control circuit operates in a first mode, a second mode, and a transition, wherein the primary switch control circuit operates in the second mode after the transition has been completed.

Abstract: A switched mode power converter has an energy transfer element that delivers an output signal to a load. A power switching device coupled to the primary side of the energy transfer element regulates a transfer of energy to the load. A secondary controller is coupled to receive a feedback signal and output a pulsed signal in response thereto. A primary controller is coupled to receive the pulsed signal and output a drive signal in response thereto, the drive signal being coupled to control switching of the power switching device. A compensation circuit generates an adaptively compensated signal synchronous with the pulsed signal. The adaptively compensated signal has a parameter that is adaptively adjusted in response to a comparison of the feedback signal with a threshold reference signal. The parameter converges towards a final value that produces a desired level of the output signal.

Abstract: A power converter includes an energy transfer element coupled between an input and an output of the power converter. A switch is coupled to the energy transfer element and a control circuit. The control circuit includes a drive signal generator to generate a drive signal to control switching of the switch to regulate the output of the power converter. An event detection circuit is coupled to the drive signal generator to indicate if a switching period of one switching cycle of the drive signal exceeds a threshold switching period. An event counter circuit is coupled to the event detection circuit to render dormant the drive signal generator for a period of time determined by a timer circuit if the event detection circuit indicates a period of a switching cycle of the drive signal exceeds the threshold switching period for a threshold consecutive number of switching cycles.

Abstract: A power converter includes a primary winding and multiple output windings to provide multiple independently controlled and regulated outputs with a common return line. The outputs are coupled to independently regulate constant current, constant voltage, or both constant current and constant voltage outputs. A secondary control block is coupled to control a synchronous rectifier switch coupled to the common return line to synchronize switching with a primary side power switch to provide complementary conduction of the primary winding and the multiple output windings. A plurality of controlled power pulse switches is coupled to the multiple output windings. A request of a power pulse from each of the outputs is transferred through the secondary control block to a primary switch control block to turn on the primary side power switch to transfer a power pulse to the multiple output windings and through controlled power pulse switches to the outputs.

Abstract: A switch having a drain terminal, a source terminal and a control terminal. The switch comprises a normally-on device including a first terminal, a second terminal, and a control terminal, a normally-off device including a first terminal, a second terminal, and a control terminal, and a clamp circuit. The first terminal of the normally-on device is the drain terminal of the switch and the control terminal of the normally-on device is coupled to the source terminal of the switch. The control terminal of the normally-off device is coupled to the control terminal of the switch. The second terminal of the normally-off device is the source terminal of the switch, and the first terminal of the normally-off device is coupled to the second terminal of the normally-on device. The clamp circuit coupled across the normally-off device and comprises a first transistor coupled to the first terminal of the normally-off device.

Abstract: A heterostructure semiconductor device includes a first active layer and a second active layer disposed on the first active layer. A two-dimensional electron gas layer is formed between the first and second active layers. A sandwich gate dielectric layer structure is disposed on the second active layer. A passivation layer is disposed over the sandwich gate dielectric layer structure. A gate extends through the passivation layer to the sandwich gate dielectric layer structure. First and second ohmic contacts electrically connected to the second active layer. The first and second ohmic contacts are laterally spaced-apart, with the gate being disposed between the first and second ohmic contacts.

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 includes a first power circuit, a second power circuit, and a charging control circuit. The first power circuit is coupled to a bypass terminal and a first terminal to be coupled to receive charge from a secondary winding. The first power circuit transfers charge from the first terminal to the bypass terminal. The second power circuit is coupled to the bypass terminal and a second terminal to be coupled to a receive charge from an output of a power converter. The second power circuit transfers charge from the second terminal to the bypass terminal. The charging control circuit controls which of the first and second power circuits transfers charge to the bypass terminal.

Abstract: A method of turning on a power semiconductor switch includes receiving a first signal that characterizes a switch-on behavior of the power semiconductor switch, and detecting two or more phases of the switch-on behavior of the power semiconductor switch in response to the first signal. The method further includes detecting a peak indicative of a phase transition between the two or more phases, generating a phase signal indicative of the two or more phases, and providing a variable current to a control input of the power semiconductor switch in response to the first signal.

Abstract: A switching circuit with reverse current prevention for use in a Buck converter includes a power switch coupled to a coupling node, which is an interconnection point of a power switch, an inductor and a freewheeling diode of the Buck converter. The inductor is coupled between the coupling node and an output of the Buck converter, and the freewheeling diode is coupled between coupling node and an output return of the Buck converter. A controller is coupled to receive a feedback signal to control switching of the power switch to regulate a transfer of energy from the input to the output of the Buck converter. A reverse current prevention circuit is coupled to detect a reverse current condition of the power switch to generate an inhibit signal to inhibit the power switch from receiving a drive signal to prevent a reverse current through the power switch.

Abstract: A power converter controller includes a primary controller configured to operate in a first mode to control a power switch with a primary switching pattern. A communication link is coupled to the primary controller. A secondary controller coupled to the communication link. The secondary controller is galvanically isolated from the primary controller. The secondary controller is configured to initiate a transition operation with the primary controller to take control of the power switch with one or more control signals through the communication link. The primary controller is configured to acknowledge receipt of the one or more control signals through the communication link to the secondary controller and transition from the first mode to a second mode.

Abstract: Circuitry for soft shutdown of a power switch and a power converters that includes circuitry for soft shutdown are described. In one aspect, circuitry for soft shutdown of a power switch includes a sense input to be coupled to a power switch receive a signal representative of current passing through the power switch, a comparator to compare the signal with an overcurrent threshold indicative of an overcurrent condition of the power switch and to output a triggering signal in response to the comparison indicating the overcurrent condition, and a gating transistor to be coupled to a control terminal of the power switch, the gating transistor configured to divert a portion of a drive signal away from the control terminal of the power switch in response to the triggering signal.

Abstract: An integrated circuit package includes a portion of a lead frame disposed within an encapsulation. The lead frame includes a first conductor including a first conductive loop and a third conductive loop disposed substantially within the encapsulation. A second conductor formed in the lead frame is galvanically isolated from the first conductor and includes a second conductive loop disposed substantially within the encapsulation proximate to the first conductive loop to provide a communication link between the first and second conductors. The third conductive loop is wound in an opposite direction relative to the first conductive loop. A transmit circuit is disposed within the encapsulation and is coupled to the second conductor to provide a transmitter current. A receive circuit is disposed within the encapsulation and is coupled to the first conductor to receive a transmitter induced signal in response to the transmitter current.

Abstract: A circuit for regulating an output level of a power converter includes an adjustment circuit to be coupled to a receive a feedback signal representative of an output level of the power converter. The adjustment circuit is coupled to generate a comparison result signal. A control circuit is coupled to receive the comparison result signal and an oscillating signal. A switch including a first terminal, a second terminal and a control terminal is coupled to the control circuit. The control circuit is coupled to generate a control signal to control switching of the switch. The switch is operable to couple or decouple the first terminal and the second terminal in response to the control signal received at the control terminal. The control signal is responsive to the oscillating signal and to a change in the comparison result signal.

Abstract: A signal transmission system for communicating across galvanic isolation includes a magnetic coupling having a transmitter-side inductor and a receiver-side inductor. The transmitter is coupled to the transmitter-side inductor, is referenced to a first potential, and includes a pulse generator coupled to output to the transmitter-side inductor a first state representation that represents a first logic state with multiple transitions, and a second state representation that represents a second logic state with multiple transitions. The pulse generator in outputting the first state representation is coupled to output a first information portion that includes the multiple transitions of the first state representation, and a first initial delay portion having a duration longer than a duration of the multiple transitions of the second state representation.

Abstract: A controller includes a switch controller coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a drain current through the power switch. The switch controller is coupled to generate a drive signal to control switching of the power switch in response to the current sense signal and a modulated current limit signal to control a transfer of energy from an input to an output of the power converter. A control modulator is coupled to generate a first signal. A jitter modulator is coupled to generate a second signal. The second signal is a periodic signal having a modulation time period that is greater than a switching period of the drive signal. An arithmetic operator circuit is coupled to generate the modulated current limit signal in response to the first signal and the second signal.

Abstract: A power converter includes an energy transfer element, a cascode circuit including a low voltage switch and a normally-on switch coupled to the energy transfer element, and a controller coupled to control switching of the cascode circuit. The controller includes a current sense circuit to generate a current limit signal and an overcurrent signal in response to a source signal and first and second sense finger signals from the cascode circuit, a control circuit to generate a control signal in response to the current limit signal and the overcurrent limit signal, and a drive circuit to generate a drive signal in response to the control signal to control the switching of the low voltage switch. The drive signal provided by a first stage is coupled not to fully enhance the low voltage switch, and provided by a second stage is coupled to fully enhance the low voltage switch.

Abstract: Apparatus and methods for sequencing outputs in a multi-output power converter system are disclosed herein. During start-up multiple CC/CV outputs may be sequenced so that energy is first provided to a highest voltage secondary output and subsequently provided to a lowest voltage secondary output. Additionally, control may be exerted so as to concurrently and monotonically increase voltages during at least part of the start-up transient; and concurrent control may be further implemented using control circuitry and a variable reference generator. In some embodiments a variable reference may be generated from a capacitor voltage.