Abstract: A method for controlling a power converter switch includes operating the power converter switch in first, second, and third duty cycle control modes in response to a feedback signal representative of an output of the power converter. The first duty cycle control mode includes modulating a peak switch current of the power converter switch in response to the feedback signal, and switching the power converter switch at a substantially fixed first switching frequency value. The second duty cycle control mode includes modulating the switching frequency in response to the feedback signal, and maintaining the peak switch current substantially at a peak switch current threshold value. The third duty cycle control mode includes modulating the peak switch current of the power converter switch in response to the feedback signal, and switching the power converter switch at a substantially fixed second switching frequency value.

Abstract: A controller for use in a power converter includes a drive circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from a power converter input to a power converter output. An input is also included to receive an enable signal including enable events responsive to the power converter output. The drive circuit is coupled to turn ON the power switch in response to the enable events, and turn OFF the power switch in response to a power switch current reaching a current limit threshold. A current limit threshold generator is coupled to receive the drive signal from the drive circuit to vary the current limit threshold at a variable rate in response to the enable events of the enable signal.

Abstract: A high-voltage field effect transistor (HFET) includes a first active layer, a second active layer, and a layer of electrical charge disposed proximate to the first active layer and the second active layer. A gate dielectric is disposed proximate to the second active layer. A contact region in the HFET includes a contact coupled to supply or withdraw charge from the HFET, and a passivation layer disposed proximate to the contact and the gate dielectric. An interconnect extends through the passivation layer and is coupled to the contact. An interlayer dielectric is disposed proximate to the interconnect, and a plug extends into the interlayer dielectric and is coupled to the first portion of the interconnect.

Abstract: A semiconductor device includes a heterostructure field effect transistor (HFET) having an active region in a semiconductor film between a source electrode and a drain electrode, where a gate electrode is over a portion of the active region and is configured to modulate a conduction channel in the active region. The semiconductor device also includes a first passivation film over the active region and an encapsulation film over the first passivation film. A first metal pattern is disposed on the encapsulation film, and the first metal pattern includes a shield wrap over the majority of the active region and is electrically connected to the source electrode. A gap is defined in the first metal pattern and the gap separates the shield wrap from a portion of the first metal pattern that is connected to the drain electrode, and the gap is not formed over the active region.

Abstract: A power converter controller includes a high side signal interface circuit that includes a common mode cancellation circuit that is coupled to generate a fourth current signal representative of an OFF signal referenced to a bypass voltage during an initial state, and a first current signal in response to an ON signal being pulled to a lower value relative to the OFF signal to turn ON a high side switch. The common mode cancellation circuit generates a common mode rejection signal in response to the first and fourth current signals. A first current hysteresis comparator receives the first and fourth current signals, the common mode rejection signal, and a drive signal to generate a first output signal. A drive signal generated in response to the first output signal in a presence of a common mode voltage caused by slewing at a half bridge node.

Abstract: An overvoltage detection circuit for a power converter a current augmentation circuit coupled to receive a sense signal representative of an output voltage of the power converter only during a portion of an off time of a power switch of the power converter. The current augmentation circuit is further coupled to output an augmented signal. A detection circuit is coupled to receive the augmented signal from the augmentation circuit and a power signal representative of a rectified version of the sense signal at a same input terminal. The detection circuit is operable to output an overvoltage detection signal based at least in part on the augmented signal, the overvoltage detection signal being representative of an overvoltage condition in the output voltage of the power converter.

Abstract: A controller includes a first control circuit coupled to an input side of a power converter. The first control circuit includes a timing and delay circuit and a switch selection circuit. A second control circuit is coupled to an output side of the power converter. The second control circuit includes a valley detection circuit and a synchronous rectifier control circuit. A third control circuit is coupled to the input side of the power converter. The third control circuit is coupled to drive an auxiliary switch coupled to an input side of an energy transfer element. The first control circuit is coupled to alternately drive a main switch, which is coupled to the input side of the energy transfer element, and the auxiliary switch in response to a command signal to transfer energy from the input side to the output side of the energy transfer element to drive a load.

Abstract: A switch having a first terminal, a second terminal and a control terminal. The switch includes a normally-on device with a first terminal, a second terminal, and a control terminal. The first terminal of the normally-on device is the first terminal of the switch. The control terminal of the normally-on device is coupled to the second terminal of the switch. A normally-off device includes a first terminal, a second terminal, and a control terminal. 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 second terminal of the switch. The first terminal of the normally-off device is coupled to the second terminal of the normally-on device. A clamp circuit is coupled across the normally-off device. The clamp circuit is coupled to clamp a voltage of the first terminal of the normally-off device to a threshold.

Abstract: A communication system for use in a switching module includes a low-side control block coupled to control switching of a low-side switch of the switching module. The low-side control block is further coupled to be referenced with a low-side reference system ground. A high-side control block is coupled to control switching of a high-side switch of the switching module. The high-side control block is further coupled to be referenced with a floating node of the switching module. During steady state operation, the low-side control block is coupled to send signals during each switching cycle to the high-side control block to turn the high-side switch on and off. A status update is communicated from the high-side control block to the low-side control block through a first single-wire communication link.

Abstract: A method for regulating an output of a power converter includes receiving a signal from an auxiliary winding of an energy transfer element of the power converter. The energy transfer element includes an input winding coupled to an input of the power converter, an output winding coupled to the output of the power converter, and the auxiliary winding. The signal represents a line input voltage of the power converter during at least a portion of an on time of a power switch coupled to the input winding. The signal represents an output voltage of the power converter during at least a portion of an off time of the power switch. The power switch is switched in response to the signal to regulate the output of the power converter.

Abstract: A power converter controller includes a drive circuit to generate a drive signal to control switching of a power switch. The drive circuit generates the drive signal in response to a current sense signal, a current limit signal, a frequency skip signal, and a hold signal. A current limit generator generates the current limit signal in response to a load. A frequency detection circuit generates the frequency skip signal in response to the drive signal to indicate when an intended frequency of the drive signal is within a frequency window. The current limit signal remains fixed for at least a switching cycle when the intended frequency is within the frequency window. A first latch generates the hold signal to control the current limit generator to hold the current limit signal. The first latch generates the hold signal in response to the frequency skip signal and a feedback signal.

Abstract: A device (442) for producing a dynamic reference signal (UREF) for a control circuit for a power semiconductor switch comprises a reference signal generator (442) for providing a dynamic reference signal (UREF), which has a stationary signal level after elapse of a predefined time following a switching process of the power semiconductor switch, a passive charging circuit (450) which is configured to increase a signal level of the dynamic reference signal in reaction to a switching of a control signal of the power semiconductor switch from an OFF state to ON state for at least one part of the predefined time above the stationary signal level, in order to produce the dynamic reference signal and an output (A) for tapping the dynamic reference signal (UREF).

Abstract: An analog receiver frontend includes a first amplification circuit coupled to receive an input signal. The first amplification stage is coupled to amplify a difference between the input signal and a threshold to generate the first signal. A second amplification circuit is coupled to receive the first signal from the first amplification circuit. The second amplification circuit is coupled to amplify the first signal to generate a second signal. An output circuit is coupled to receive the second signal from the second amplification circuit. The output circuit is coupled to output a recovered signal. The recovered signal is a pulse waveform of high and low sections. An input hysteresis circuit is coupled to the output circuit to receive the recovered signal and generate a hysteresis signal. One or both of the input signal and the threshold are level shifted by the hysteresis signal in response to the recovered signal.

Abstract: A power converter includes an energy transfer element that includes a primary winding and a secondary winding, and is coupled to transfer energy between the primary winding and the secondary winding. An enable circuit is coupled to generate an enable signal in response to a feedback signal falling below a threshold. A controller is coupled to control switching of a power switch coupled to the primary winding to regulate an output of the power converter. The controller includes a drive circuit coupled to output a drive signal in response to the enable signal, and a current limit threshold generator coupled to output a current limit threshold signal to the drive circuit in response to the drive signal. The current limit threshold signal varies in response to a time between events of the enable signal over a range of loads coupled to the output of the power converter.

Abstract: A power converter includes an energy transfer element and a circuit coupled to the input of the power converter. The circuit includes a switch and a control circuit capable of detecting whether an AC voltage source is coupled to the input, or uncoupled from the input within a first predetermined time. The control circuit is coupled to drive the switch in a first operating mode when the AC voltage source is coupled, drive the switch in a second operating mode when the AC voltage source is uncoupled, and is capable of discharging a capacitance coupled between input terminals of the power converter to a threshold voltage level through a discharge path and through the switch within a second predetermined time. An RC time constant of the discharge path is less than or equal to one second and the threshold voltage level is less than or equal to ten volts.

Abstract: A controller for use in a power factor correction converter includes a power factor enhancer that includes a zero-crossing detector coupled to receive an ac line input voltage signal and is coupled to output a zero-crossing signal. A peak detector is coupled to receive the ac line input voltage signal and the zero-crossing signal and is coupled to output a peak signal. A peak modulator is coupled to receive the zero-crossing signal and is coupled to generate a peak modulation function. A line feed forward function generator is coupled to generate a line feed forward function. A multiplier is coupled to receive the peak modulation function and the line feed forward function, and is coupled to output a pre-distortion signal each half line cycle.

Abstract: A driver circuit for use in a controller includes a signal generator coupled to generate a first control signal and a second control signal in response to a drive signal that is coupled to control switching of a secondary switch that is to be coupled to the driver circuit and referenced to a reference voltage that is greater than a ground reference voltage. A second switch is coupled to be controlled by the second control signal such that the reference voltage is substantially applied to a control of the secondary switch when the drive signal controls the secondary switch to be off. A first switch is coupled to be controlled by the first control signal such that the sum of the reference voltage and a first voltage is substantially applied to the control of the secondary switch when the drive signal controls the secondary switch on.

Abstract: A driver circuit for use in a controller includes a signal generator coupled to generate a first control signal, a second control, and a third control signal in response to a drive signal that is coupled to control switching of a selection switch that is coupled to the driver circuit and referenced to an output voltage that is greater than a ground reference voltage. A first switch is coupled to selectively couple a first voltage to a first terminal of the controller in response to the first control signal. A second switch is coupled to selectively couple a second voltage to a second terminal of the controller in response to the second control signal. A third switch is coupled to selectively couple the second terminal of the controller to a third terminal of the controller in response to the third control signal.

Abstract: A dimmer interface circuit for reducing ringing on a drive signal to a lighting device. The dimmer interface circuit controls brightness of the lighting device and receives a brightness control voltage from a dimmer circuit. The dimmer interface includes a voltage converter and a charge store, which is coupled to receive charge from an inductive component to convert the brightness control voltage to the converter output voltage. The dimmer interface circuit also includes control circuitry to control the voltage converter such that a difference between the brightness control voltage and the converter output voltage at a time of transition of the brightness control voltage is closer to a target voltage difference.

Abstract: A circuit for use with a Universal Serial Bus (USB) socket includes a power converter coupled to receive an input voltage at an input terminal and coupled to provide an output voltage at an output terminal. A transistor is coupled between the output terminal of the power converter and a bus voltage terminal of the USB socket. A USB communication controller is coupled to the USB socket. The USB communication controller includes an output terminal coupled to a control terminal of the transistor. A bleeder circuit is coupled between the output terminal of the USB communication controller and the bus voltage terminal of the USB socket.