Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: Systems and methods for operating a transistor rectifier unit are provided. Aspects include providing a first transformer output and a second transformer output, providing a plurality of rectifier circuits, wherein the plurality of rectifier circuits comprises a first rectifier coupled to the first transformer output and a second rectifier coupled to the second transformer output, and wherein the first rectifier comprises a first output voltage and the second rectifier comprises a second output voltage, operating a plurality of switches based on a plurality of operational modes, wherein the plurality of operational modes comprises a first mode, a second mode, and a third mode, and wherein the plurality of switches comprises a first switch, a second switch, and a third switch.

Abstract: A power converter includes a PFC circuit, a first capacitor, a second capacitor and an auxiliary circuit. The PFC circuit provides a first intermediate voltage to the first capacitor. The auxiliary circuit includes a first auxiliary branch circuit and a second auxiliary branch circuit. When the first auxiliary branch circuit is enabled, and the first intermediate voltage is transmitted to the second capacitor through the first auxiliary branch circuit. When the second auxiliary branch circuit is enabled, the first intermediate voltage is boosted by the second auxiliary branch circuit, so that a second intermediate voltage is provided by the second capacitor. While an operation state of the load is switched between a light load condition and a heavy load condition, one of the first auxiliary branch circuit and the second auxiliary branch circuit is selectively enabled.

Abstract: A control method for a power supply apparatus is provided. Firstly, at least one of an output voltage or an output current of the resonant converter is sampled. Then, an error signal is generated according to a reference value and at least one of the output voltage or the output current. While the resonant converter is in a burst mode, a first switching signal and a chopping signal are generated according to the error signal. The chopping signal has a chopping period and a duty cycle. The chopping period and the duty cycle are dynamically adjusted according to the error signal. Then, a second switching signal is generated according to the chopping signal and the first switching signal. A switch unit of the resonant converter is turned on or turned off according to the second switching signal.

Abstract: An electric power conversion apparatus includes a first inverter electrically connected to one end of each of phase windings of a motor, and a second inverter electrically connected to the other end of each of the phase windings, and a neutral point potential setting circuit electrically connected to the first inverter to set a potential of a neutral point in the first inverter when the first inverter is determined to be in an abnormal state.

Abstract: The disclosure is directed to techniques for a pass element in a linear regulator circuit. The pass element is configured with a transistor with a low input capacitance that provides current to the load for light current demand levels. When the output current exceeds a predetermined threshold, the pass element is configured to turn on a second transistor to provide the additional current. The configuration of the pass element with the regulator circuit causes the regulator circuit to operate with a low quiescent current and with large bandwidth for fast response to load changes.

Abstract: Disclosed is a universal input voltage detection system for a flyback converter having a transformer coupled between an input and an output of the flyback converter. The transformer includes a primary winding coupled to the input of the flyback converter to receive an input voltage and a secondary winding coupled to the output of the flyback converter. The universal input voltage detection system comprises a controller, coupled to a switch, at a primary winding side of the transformer. The switch is coupled to the primary winding of the transformer and a current through the primary winding is generated when the switch is turned on. The controller is configured to operate in either continuous conduction mode (CCM) or discontinuous conduction mode (DCM) and indirectly detect the input voltage to the flyback converter based on the current through the primary winding generated while the switch is turned on.

Abstract: A switch detection circuit is provided that senses the voltage on a rectifying component for rectifying a secondary winding current through a secondary winding of a flyback converter's transformer to determine whether a power switch transistor attached to a primary winding of the transformer has ceased cycling.

Abstract: A power supply includes a voltage regulator, a transistor, a current-to-voltage transform circuit, and a comparator. The voltage regulator receives a control signal, a source voltage, and a control voltage, and outputs a supply voltage according to the control voltage and the control signal. The transistor has a first terminal receiving the source voltage, and a control terminal coupled to the voltage regulator. The current-to-voltage transform circuit has a first terminal coupled to a second terminal of the transistor, a second terminal for receiving a reference voltage. The comparator has a first input terminal for receiving a comparison signal, a second input terminal coupled to the first terminal of the current-to-voltage transform circuit, and an output terminal for outputting the control voltage.

Abstract: A voltage reference includes a flipped gate transistor coupled between a first node configured to carry an operating voltage and a second node configured to carry a negative supply voltage. A first transistor and a second transistor are coupled in series between the first node and the second node, a gate of the first transistor is coupled with a gate of the flipped gate transistor, and a gate of the second transistor is configured to receive the negative supply voltage. An output node between the first transistor and the second transistor is configured to output a reference voltage, and a current source coupled between the output node and the second node is configured to supply a current through the first transistor based on a current through the flipped gate transistor.

Abstract: A switching circuit may include first and second switching elements that are connected in parallel with each other. A controller may be configured to selectively perform either a first switching control to drive the first switching element or a second switching control to drive the second switching element. The first switching element may be constituted mainly of a first semiconductor material, and the second switching element may be constituted mainly of a second semiconductor material having a narrower band gap than the first semiconductor material. The second switching element may be larger in size than the first switching element. The controller may be configured to switch to the second switching control when an instruction value and/or an actual value of the current exceeds a predetermined threshold value while performing the first switching control.

Abstract: Voltage converter having light-load control. In some embodiments, a voltage converter can be configured to receive an input voltage and generate a regulated voltage. Such a voltage converter can include a determining unit configured to determine whether the voltage converter is in a first load state. The voltage converter can further include a driving unit in communication with the determining unit, and be configured to generate a first driving signal when the voltage converter is in the first load state. The voltage converter can further include a switching unit in communication with the driving unit, and be configured to route the first driving signal to a control element of the voltage converter when the voltage converter is in the first load state, and be further configured to route a second driving signal to the control element when the voltage converter is in a second load state.

Abstract: An embodiment of a power-supply controller includes first and second circuits. The first circuit is operable to cause a first current to flow through a first phase of a power supply. And the second circuit is operable to cause the second phase of the power supply to operate in a reduced-power-dissipation mode for at least a portion of a time period during which a second current magnetically induced by the first current flows through the second phase.

Abstract: Reverse currents are prevented using existing components, like a primary-side current transformer. A power supply includes an isolation transformer, a switch, a synchronous rectifier, a smoother, a controller with a signal generator circuit that outputs main drive signals for main switching elements of the switch and drive signals for synchronous rectifier elements of the synchronous rectifier, and a current detector that has a current transformer, detects a current flowing to the switch, and outputs an output current detection signal. The controller includes an OR circuit that generates an OR signal for the main drive signals and a reverse current determination circuit that determines whether a reverse current has occurred based on the OR signal and the output current detection signal. When the occurrence of a reverse current has been determined, outputting of the main drive signals and the drive signals is stopped.

Abstract: The present invention discloses a semiconductor assembly. The semiconductor assembly comprises a fully controlled power electronic device and a snubber circuit, wherein the snubber circuit is connected to the fully controlled power electronic device in parallel; the snubber circuit comprises a capacitor (C), an inductor (L), a resistor (R), a diode (D) and a half controlled power electronic device (A1); the inductor (L) and the half controlled power electronic device (A1) are connected in series and are together connected to the resistor (R) in parallel; and the diode (D) and the resistor (R) are connected in parallel and are together connected to the capacitor (C) in series.

Abstract: In one form, a control circuit is adapted for use with a power converter having an inductor and a switch switching the inductor in response to a switching signal to regulate an output voltage of the power converter. The control circuit includes a slow feedback path, a fast feedback path, an integrator, a comparator, and a drive circuit. The slow feedback path provides a ripple signal in response to an average value of the output voltage. The fast feedback path provides a feedback signal in response to the output voltage. The integrator provides an error signal in response to a sum of the feedback signal and the ripple signal. The comparator provides a comparison output signal in response to a comparison of the error signal and a threshold voltage. The driver circuit provides the switching signal in response to the comparison output signal.

Abstract: The disclosure describes techniques for measuring the average output current of a power converter circuit by determining peaks valleys in the output current. A current monitoring circuit may include an averaging unit, which may sample the output current during a current peak as well as during a current valley. During a hold phase the averaging unit may output a signal proportional to the average output current based on the sampled peak current and sampled valley current. In some examples, the averaging unit may include three functional units. A first unit may be configured to determine the output current, a second block may be configured to hold the previously determined peak current and a third block may be configured to hold the previously determined valley current. In this manner the averaging unit may continuously output a signal proportional to the average output current of the power converter.

Abstract: A power supply apparatus of the present invention has a power factor correction circuit that corrects a power factor; a voltage converter connected to a secondary side of the power factor correction circuit; a power control unit that outputs a first signal for turning the power factor correction circuit on, and outputs a second signal for turning the voltage converter on; and a signal output unit that, in accordance with having being inputted with the first signal and the second signal, outputs a signal for turning the voltage converter on.

Abstract: Devices and methods are provided for controlling dead-time of a direct current to direct current (DC-DC) converter. A control circuit includes a first transistor having a source/drain terminal coupled to an output voltage of the DC-DC converter configured to provide current based on the output voltage. The control circuit also includes a digital up/down counter having an output terminal electrically coupled to an input terminal of a delay cell of the DC-DC converter. A current sensing circuit of the control circuit is electrically coupled to an input terminal of the digital up/down counter configured to receive the current and drive the digital up/down counter based on the current.

Abstract: According to one embodiment, a power converter circuit includes a resonant circuit coupled to an alternating current (AC) voltage source to convert a first AC voltage to a first AC current and an AC to direct current (AC/DC) converter coupled to the resonant circuit, where the AC/DC converter is to convert the AC current to a DC current. The power converter circuit further includes an inverter coupled to the AC/DC converter to convert the DC current to a second AC current, an AC filtering circuit coupled to an output of the inverter, and a load coupled to the output of the inverter to convert the second AC current to a second AC voltage.