Abstract: In accordance with an embodiment, a method of operating a switched-mode power converter includes driving a switching element in successive drive cycles, in which the switching element is driven to switch on for an on-period and subsequently driven to switch off for an off-period; sampling a feedback signal two or more times during the drive cycles, where the feedback signal includes a signal representative of an operation parameter of the switched-mode power converter and noise. The method further includes filtering the sampled feedback signal to extract the signal representative of the operation parameter from the sampled feedback signal and controlling the switching element according to the filtered feedback signal.

Abstract: A switching control circuit for controlling a multi-channel switching circuit can include: a logic control circuit that receives an external operation signal, and generates an enable signal, a trigger signal, and an order signal; a reference voltage regulation circuit that receives the enable signal, the trigger signal, the order signal, and a plurality of input voltage signals, and generates an adjustable reference voltage signal, where the reference voltage regulation circuit is also configured to select one of the plurality of input voltage signals based on the order signal; a feedback control circuit that receives the reference voltage signal, the plurality of input voltage signals, and the output voltage signal, and generates a feedback control signal; and a channel selection circuit that receives the order signal and the feedback control signal, and generates switching control signals to control switching operations of the multi-channel switching circuit.

Abstract: A power converter includes an input power source, a synchronous rectifier and a controller. The synchronous rectifier includes a plurality of actively controlled switches coupled in parallel and configured to rectify current delivered from the input power source to a load. The controller is operable to issue a first control signal for driving a first one of the actively controlled switches and issue a second control signal for driving a second one of the actively controlled switches. The first control signal is a different control signal than the second control signal so that the first actively controlled switch is controllable separately from the second actively controlled switch. The first actively controlled switch has a higher current-carrying capacity than the second actively controlled switch.

Abstract: A voltage regulation system for providing power to a load is provided. The voltage regulation system includes a voltage regulator operable to set an operating voltage of the load at a first voltage level which corresponds to a first voltage requirement of the load, receive a second voltage requirement of the load which is different than the first voltage requirement and produce a voltage ramp from the first voltage level to the second voltage level. The voltage regulator is further operable to transition the operating voltage from the first voltage level to the second voltage level at a same ramp rate as the voltage ramp and with a lag between the voltage ramp and the transition in the operating voltage.

Abstract: A regenerative variable frequency drive includes an active converter connected to a DC bus that is connected to a first inverter that converts DC power to variable frequency, three phase AC power, and variable frequency, three phase AC power to DC power, and to a second inverter that converts DC power to three phase AC sine wave power. The converter converts single phase AC power to DC power and DC power to single phase AC power, and maintains a selected voltage on the DC bus. The converter has an active rectifier and a controller that drives the rectifier with a pulse width modulation according to a hybrid voltage switching scheme that switches the rectifier according to a unipolar voltage switching scheme through most of each cycle and switches the rectifier according to a bipolar voltage switching scheme around each zero crossing.

Abstract: A power conversion device includes first and second terminals connected to a DC power source, third and fourth terminals connected to a commercial power system or a load, a transformer including a primary winding having seventh and eighth terminals and a secondary winding having fifth and sixth terminals, an inverter circuit connected between the first and second terminals and the seventh and eighth terminals, a converter circuit connected between the fifth and sixth terminals and the third and fourth terminals, a diode bridge including first and second AC input terminals connected to the fifth and sixth terminals, respectively, and first and second DC output terminals, a first capacitor connected between the first and second DC output terminals, and a first resistor connected in parallel with the first capacitor between the first and second DC output terminals.

Abstract: A reference stage includes a first transistor, a second transistor and a resistor that are connected in series from a voltage rail to a reference load. The resistor has (i) a resistance that is a function of a digital resistance-controlling value, (ii) a first terminal coupled to a gate of the first transistor, and (iii) a second terminal that has a voltage VG2 and is coupled to a gate of the second transistor. A comparator has a first input that is coupled to the resistor's second terminal. A diode-connected reference transistor is connected from the voltage rail to the comparator's second input to apply a voltage VD at the second input. An adjusting circuit adjusts the digital resistance-controlling value to cause VG2 to approach VD until the comparator's output changes state when VG2 reaches VD.

Abstract: A power-conversion apparatus includes active-semiconductor switches configured to transition between first and second states that result in corresponding first and second electrical interconnections between capacitors and at least one of first and second terminals configured to be coupled to first and second external circuits at corresponding first and second voltages, a pre-charge circuit coupled to at least one of the capacitors, and gate-driver circuits, each of which includes a control input, power connections, and a drive output. Each switch is coupled to and controlled by a drive output of one of the gate-driver circuits. Power for the gate-driver circuits comes from charge stored on at least one of the capacitors via the power connection of that gate-driver circuit.

Abstract: Embodiments of the present invention provide improved techniques and devices for reducing transformer commutation distortion caused by large load currents. Traditional power supplies which have two or more phases typically commutate a transformer during the end of each phase. When the load current is large, energy stored in the transformer's leakage inductance can cause undesirable effects during commutation. Embodiments of the present invention reduce these effects by lowering the voltage across the primary side of the transformer prior to commutation. In one embodiment, a capacitor is added to the primary side of the transformer. A switch directs current through the capacitor prior to commutation, allowing the capacitor to absorb the transformer's leakage inductance energy and lower the primary side voltage. Other suitable components, such as resistors, diodes, transistors, or additional transformer windings, may also be used to reduce the primary-side voltage prior to commutation.

Abstract: A half-bridge resonant bidirectional DC-DC converter circuit comprising a half-bridge buck-boost converter and a resonant DC-DC converter. The half-bridge buck-boost converter is coupled to an external DC power source to achieve a wide input voltage range. The resonant DC-DC converter is coupled to the half-bridge buck-boost converter to act as a later stage circuit of the half-bridge buck-boost converter. The resonant DC-DC converter is used to control the direction of the bidirectional power flow and respond to the half-bridge buck-boost converter under a fixed frequency mode to convert the input of the half-bridge buck-boost converter to an induced current.

Abstract: The switching power source device obtains a desired DC voltage by controlling the current flowing through a coil by turning on and off a switching element by a PWM control. In the PWM ON period to turn on the switching element by the PWM control, the switching power source device is enabled to switch the switching element by a first pulse signal whose cycle is shorter than the PWM cycle and whose pulse width is gradually increased, in a first period just after the start of the PWM ON period. Further, the switching power source device is enabled to switch the switching element by a PWM signal based on the PWM control after the first period in the PWM ON period has elapsed. According to this approach, it is possible to reduce the harmonic noise.

Abstract: A synchronous rectifier controller includes an exception timer, one or more blanking timers, and control logic. The control logic may detect a beginning of a conduction phase using a current sense signal. In response to detecting the beginning of the conduction phase, the control logic commences the exception timer, commences a first blanking interval, and asserts the drive signal. In response to an OFF condition being detected, the first blanking interval being elapsed, and the exception timer being running, the control logic de-asserts the drive signal and commences a second blanking interval. In response to an ON condition being detected, the second blanking interval being elapsed, and the exception timer being running, the control logic commences a third blanking interval and asserts the drive signal. The control logic may assert and de-assert the drive signal multiple times while the exception timer is running.

Abstract: A power conversion system includes an isolating transformer (30) and an output-controlling device (40). The isolating transformer (30) includes a primary winding (310) and a plurality of secondary windings (320a˜320d) coupled with the primary winding (310), and the isolating transformer (30) has a plurality of coupling distances between the secondary windings (320a˜320d). The output-controlling device (40) includes a controller (420) and a plurality of output-controlling modules (400a˜400d), wherein each one of the secondary windings (320a˜320d) is electrically connected to one of the output-controlling device (400a˜400d). The controller (420) places at least one output-controlling device (400a˜400d) in a conducting state for output a rectified power. An amount of the secondary windings (320a˜320d) coupled with the primary winding (310) is modulated for varying a leakage inductance of the power conversion system.

Abstract: A buck converter is described having a buck converter output for outputting an output supply voltage; a first power supply domain operably coupled to a power source; a second power supply domain; a power supply controller coupled to the first power supply domain, the second power supply domain and the buck converter output; wherein the power supply controller is configured to supply power to the second power supply domain from the first power supply domain or the buck converter output, in dependence of the buck converter output supply voltage. Changing the current supplied to the second power supply domain to the buck converter output may reduce the quiescent current consumption from a battery power source, prolonging battery life.

Abstract: Provided is a conversion device which can determine the presence/absence of a failure in a detection unit for detecting AC or DC voltage or current. A conversion device, including an AC-DC conversion circuit, a DC-DC conversion circuit for converting DC voltage output from the AC-DC conversion circuit and a detection unit for detecting AC or DC voltage or current, comprises an obtaining part for obtaining information indicating whether or not AC voltage is applied to the AC-DC conversion circuit, and a power supply fault determination part for determination presence/absence of a power supply fault or an open fault in the detection unit if the obtained information indicates that AC voltage is not applied to the AC-DC conversion circuit.

Abstract: A flyback converter is described that in some examples includes an integrated circuit that includes a delta-sigma converter and a cascaded integrator-comb filter configured to determine: a proportional factor, an integral factor, and a derivative factor associated with a secondary-side voltage across a secondary-side winding of the converter. The integrated circuit uses each factor to control a secondary switching element to perform synchronous rectification. In some examples, the flyback converter includes an auxiliary winding at the primary side of the transformer and a knee point voltage detection unit. The knee point voltage detection unit is configured to determine, based on an analog input indicative of a voltage at the auxiliary winding, an integral of value and detect, based on the integral value, a knee point voltage associated with the voltage at the auxiliary winding. A controller may use the detected knee point to control a primary side switch.

Abstract: An overcurrent protection control circuit detects a low set value of an output voltage from a drop in voltage at a VCC terminal below a reference voltage. The overcurrent protection control circuit switches an overcurrent limit value from a high reference voltage to a low reference voltage and switches a maximum limit value of a switching frequency from a high first maximum switching frequency to a low second maximum switching frequency. By doing so, an overcurrent limit value of a switching element and a maximum limit value of a switching frequency are set to low values and a rise in output current is suppressed.

Abstract: Control apparatus, techniques and computer readable mediums are presented to mitigate LCL filter resonance issue for voltage source converters. Two level voltage source converter with and without passive damping of LCL filter are selected for the comparative study. Control algorithms are presented to estimate the source impedance based on variable carrier PWM. Estimated source impedance is used to tune the control of the VSC to avoid the resonance of LCL filter has been presented. In situations in which LCL resonance cannot be avoided by tuning the control parameters, energy efficient techniques are disclosed to provide selective passive damping to facilitate continued power conversion system operation without significant adverse impact on system performance.

Abstract: A switching converter converts an input signal to a regulated output signal using a switch and a transformer with a primary winding and a secondary winding. A wake up management circuit receives a transformer demagnetization signal and forces by wake up pulses the switch on when the switching converter operates in a burst mode. Sampled values of the transformer demagnetization signal are received. A setting circuit sets a first peak value of the current of the primary winding. A comparison circuit compare the sampled values with a voltage threshold and the preceding sampled value. In response thereto, the first peak value of the primary winding current is either maintained or a new peak value is set.

Abstract: This disclosure describes techniques for controlling a power supply voltage for a high-side gate driver that is used in a power converter. In some examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may decouple a terminal of a charge pump capacitor from the input voltage lead, and couple the terminal of the capacitor to a reference voltage lead. In further examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may turn off both switching transistors.