Abstract: A resonant converter (10) comprising a voltage compensation circuit (72, 73) configured to generate a periodic compensation voltage signal (Vslopecompens) at a switching frequency of the converter such that conduction intervals (31, 32) are ended according to first and second voltage levels in combination with the periodic compensation signal.

Abstract: A down converter for converting an input DC voltage (Vin) into a lower output DC voltage (Vout). The down converter has on the primary side (2) an LC series resonance circuit (4) that can be connected via a first switch (S1) to the input voltage (Vin) and via a second switch (S2) to ground. On the secondary side (3), an output switch (S3) and an output capacitor (C) are each connected in parallel to the DC voltage output (Vout) and connected to each other through an inductor (L). The output switch (S3) is connected via a diode (Dr) to the input voltage (Vin) so as to divert voltage overshoots.

Abstract: The present invention relates to a control method for a soft switch circuit in a switch power supply, which controls first and second main power switch devices to be turned on and turned off constantly to generate an alternating main power filter current, and controls forward and backward auxiliary switch devices to be turned on and turned off to generate an intermittent alternating resonant current across a resonant branch in the same direction as the main power filter current to thereby achieve zero-voltage turn-on of the first and second main power switch devices; and further controls the forward and backward auxiliary switch devices to be turned on and turned off to generate compensation currents across the resonant branch in the opposite direction to the alternating main power filter current in at least a period of time during resting of the resonant current to thereby accomplish a charging and discharging process of resonant capacitors in a dead time.

Abstract: A control device for a rectifier of a switching converter, the converter powered by an input voltage and suitable for providing an output current. The rectifier is suitable for rectifying an output current of the converter and includes at least one transistor. The control device is suitable for driving the at least one transistor. The control device has a first circuit suitable for identifying the start and the end of every converter switching half-cycle and measuring the duration thereof, a second circuit suitable for generating a signal for turning on the transistor after a given number of measured converter switching half-cycles and when the output current of the converter becomes greater than a reference current.

Abstract: A resonant power conversion apparatus including a transformer-based resonant converter and first and second switch control units is provided. The transformer-based resonant converter includes a primary switch circuit and a secondary output circuit configured to provide an output voltage to a load. The first switch control unit is configured to control an ON/OFF operation of the primary switch circuit in response to a status of the load. The second switch control unit is configured to determine whether to activate or inactivate the first switch control unit. When the status of the load is the light-loading or the no-loading, the first switch control unit intermittently controls the ON/OFF operation of the primary switch circuit, and meanwhile, the first switch control unit is inactivated during the primary switch circuit is disabled, so as to substantially reduce the light-loading or no-loading loss of the resonant power conversion apparatus.

Abstract: We describe a resonant discontinuous power converter including a magnetic energy storage device, and a bipolar junction transistor (BJT) switch having a collector terminal coupled to repetitively switch power from the input on and off to said magnetic energy storage device such that power is transferred from the input to the output. During an off-period of said BJT switch a voltage on said magnetic energy storage device and on said collector terminal of said BJT is at least partially resonant. The power converter includes a voltage clamping circuit to clamp a base voltage on a base terminal of said BJT during a resonant portion of said off-period to limit an excursion of a collector voltage on said collector terminal of said BJT towards or beyond an emitter voltage of said BJT during said resonant portion of said off-period, in particular to inhibit reverse bias of a base emitter junction of the transistor.

Abstract: A switching power source device which has main switch elements which switch a current path of the series resonant circuit, and a transformer which induces a current to a secondary side, controls the main switch elements on a primary side. Synchronous rectification switch elements are turned ON and OFF in response to one of the main switch elements. A synchronous control circuit which turns the synchronous rectification switch element ON in synchronization with an ON timing of the main switch element, or a conduction timing of internal diodes in the synchronous rectification switch elements detected by an inter-terminal voltage signal of the synchronous rectification switch element, whichever timing is later, determines a maximum ON width of the synchronous rectification switch element in accordance with a delay time of the conduction timing of the internal diodes with respect to the ON timing of the main switch element.

Abstract: An apparatus and a method for converting power from a power input to an DC output voltage or current, which apparatus has a serial resonance converter, where a first feedback circuit is connected from the output terminal to an error amplifier, where the apparatus further has a second feedback circuit with at least one first resistor that is connected to a coil and to ground, which second feed back circuit connects the line between the first resistor and the coil and towards an inverting integrator, the output of which is connected through a second capacitor to a second input at a control circuit. As a result, the oscillating frequency is under influence of a signal that depends on the voltage generated in the resistor connected in serial to the coil or transformer.

Abstract: A DC-DC converter includes a waveform generator that generates an output waveform for the DC-DC converter based on a DC input voltage. A rectifier rectifies the output waveform from the waveform generator to generate a rectified voltage for the DC-DC converter. A tank circuit having an inductor and a capacitor can be configured to have a resonant frequency that is correlated with a frequency of the output waveform, wherein the capacitor of the tank circuit also functions as a filter for the DC-DC converter.

Abstract: The present invention is to provide a series resonant converter with an overload delay and short-circuit protection mechanism, which includes a voltage sensing circuit for sensing a voltage ripple level on a primary side of a transformer thereof, that corresponds to a load on a secondary side of the transformer, and generating and sending a DC detection level to an overload delay circuit and a short-circuit protection circuit thereof accordingly. The overload delay circuit and the short-circuit protection circuit are able control the converter through a resonant controller chip to output different currents according to magnitude of the load on the secondary side and maintain stable operation for a predetermined delay time even if the secondary side is overloaded, however, once the secondary side is short-circuited, the converter is turned off instantly. Thus, the converter is effectively prevented from damage which may otherwise result from sustained overload or short circuit.

Abstract: A method and circuit for controlling a resonant DC/DC converter which adjusts an output voltage by changing a turn-on frequency of input switch devices of a resonant circuit of the converter. The method extends the range of the output voltage of the resonant circuit by adjusting the duty ratio of the switch devices based on the feedback signal of the load circuit. The method and circuit uses two modes to control resonance of the DC/DC converter-frequency modulation and frequency modulation plus pulse width modulation. Frequency modulation is used when the operating frequency of the power supply is low. Frequency modulation plus pulse width modulation is used when the operating frequency of the power supply is too high.

Abstract: The invention provides a power supply apparatus for supplying electric power to a capacitive load. The apparatus has a transformer, a positive half-period driver and a negative half-period driver supplying positive and negative half-periods of voltage to the first coil. The second coil forms an electric resonance circuit and supplies electric voltage to the load. Zero crossings of the voltage supplied to the first coil are determined from a third coil on the transformer, and alternation between positive and negative half-periods of voltage supplied to the first coil is done at the zero crossings of the voltage supplied to the first coil.

Abstract: The configurations of a resonant converter system and a controlling method thereof are provided. The proposed resonant converter system includes a resonant converter receiving an input voltage for outputting an output voltage, a rectifying device having a first rectifying switch and a synchronous rectification control circuit coupled to the resonant converter and including a signal generation apparatus generating a weighted turn-off signal to turn off the first rectifying switch at a zero crossing point of a first current flowing through the first rectifying switch.

Abstract: The resonant switching power supply device is equipped with switching elements QH and QL connected in series to an input direct-current power source Vin, a transformer T1 having secondary windings S1 and S2 and a primary winding P1, a resonant circuit where the primary winding P1 and a current resonant capacitor Cri are connected in series and which is connected in parallel to any one of the switching elements, and a rectifying circuit (D1+D2+Co) connected to the secondary winding to obtain an output voltage Vo; the transformer T1 is equipped with a primary winding P2 closely coupled to the primary winding P1, one terminal of the primary winding P2 is connected to one or the other terminal of the primary winding P1. By the other terminal is an open circuit at any time, it suppresses the switching frequency raised at the time of light load.

Abstract: An inductive electronic module comprises a planar core element having an inner limb and at least two lateral limbs, to which winding arrangements are assigned for forming a transformer. First and second partial windings are formed on first and second of the lateral limbs such that a resulting magnetic flux of the first planar winding arrangement is cancelled in the inner limb and the second planar winding arrangement is magnetically decoupled from the first planar winding arrangement on the inner limb. The inner limb has a first core section for interacting with the second planar winding arrangement and a second core section spaced from the first core section on the core element. The second core section interacts with an additional planar winding arrangement, which forms a series connection with the second planar winding arrangement. The second core section implements a magnetically active air gap for the additional planar winding arrangement.

Abstract: Peak current in a switching converter is controlled using a closed loop to compensate for error caused by delay time in the switching transistor and control logic. A reference value is established that represents a target current value. A compensated reference value is derived from the reference value by the closed loop. A periodic inductor current is formed in the switching converter in response to the compensated reference value. An error signal is formed that is indicative of an amount of time the inductor current exceeds the target current value. The compensated reference value is dynamically adjusted by the compensation closed loop to minimize the error signal.

Abstract: In one embodiment, a quasi-resonant power supply controller is configured to select particular valley values of a switch voltage to determine a time to enable a power switch. The valleys values are selected responsively to a range of values of a feedback signal.

Abstract: A multiple-output switching power source apparatus has a series resonant circuit connected in parallel with a switch Q2 and including a primary winding and a current resonant capacitor, a first rectifying-smoothing circuit rectifying and smoothing a voltage of a secondary winding in an ON period of the switch to provide a voltage Vo1, a series resonant circuit connected in parallel with the switch and including a primary winding and a current resonant circuit, a second rectifying-smoothing circuit rectifying and smoothing a voltage of a secondary winding in the ON period of the switch Q2 to provide a voltage Vo2, and a control circuit controlling an ON period of a switch Q1 according to the output voltage Vo1 and the ON period of the switch Q2 according to the voltage Vo2 and limit the ON period of the switch Q1 if the voltage Vo2 exceeds a predetermined voltage.

Abstract: A multiple-output switching power supply unit includes: a voltage generating circuit Q1, Q2, T1a, 10a configured to generate a pulse voltage by intermittently interrupting a direct current power supply 1; a series resonance circuit including a current resonance capacitor Cri2, a primary winding P2 of a transformer T2, and a switching element Q3, the pulse voltage generated in the voltage generating circuit being applied to the series resonance circuit; a rectifying/smoothing circuit D2, C2 configured to rectify and smooth a voltage which is generated in a secondary winding S2 of the transformer, and thus to output a direct current output voltage; and a control circuit 11 configured to turn on and off the switching element based on the direct current output voltage.

Abstract: An electromagnetic resonance non-contact power transmission device includes a transmitter including a transmitter resonance element having a mechanism for discretely or continuously varying a resonant frequency, a transmitter excitation element coupled to the transmitter resonance element by electromagnetic induction, and an alternating current source for applying an alternating current at the same frequency as the resonant frequency to the transmitter excitation element, and a plurality of receivers each including a receiver resonance element having a specific resonant frequency, a receiver excitation element coupled to the receiver resonance element by electromagnetic induction, and an output circuit for outputting an electric current induced by the receiver excitation element. Electric power is transmitted selectively from the transmitter to any of the receivers having different specific resonant frequencies by changing the resonant frequency of the transmitter.

Abstract: A resonant, bi-directional, DC to DC voltage converter with loss-less (soft) switching having regulated output and capable of converting power between two, high-potential and low-potential DC voltage sources. The converter's semiconductor and magnetic components provide both, output regulation and soft switching in both (step-down and step-up) directions of power conversion which reduces total component count, cost and volume and enhances power conversion efficiency.

Abstract: A resonant converter includes: a first switching element and a second switching element, which are connected in series; a series resonant circuit, which includes a primary coil of a transformer having leakage inductance and a current resonant capacitor, and which is connected in parallel to one of the first switching element and the second switching element; a rectifying-and-smoothing circuit, which is connected to a secondary coil of the transformer, wherein an output voltage is to be supplied to a load; and a clamp circuit, which clamps a voltage between both ends of the current resonant capacitor to a predetermined voltage value, wherein, when an output current supplied from the rectifying-and-smoothing circuit to the load is higher than the predetermined current value, an output characteristic is set so that, as the output current is increased, the output voltage is decreased.

Abstract: Consistent with an example embodiment there is a method of controlling a resonant power converter; the power converter includes first and second series connected switches connected between a supply voltage line and a ground line and a resonance circuit, having a capacitor and an inductor. The resonance circuit is connected to a node connecting the first and second switches. The method comprises repeated sequential steps of closing the first switch to start a conduction interval; sampling a voltage across the capacitor to obtain a sampled voltage level; and opening the first switch to end the conduction interval when a voltage across the capacitor crosses a voltage level determined by addition of the sampled voltage level with a predetermined voltage difference; wherein controlling the predetermined voltage difference determines a power output of the resonant power converter.

Abstract: A bisynchronous resonant switching-type direct current power supply includes a power supply unit, a power factor correcting unit, a resonant converting unit, and a synchronous rectifying unit. The power supply unit includes a power supply circuit to receive an alternating current signal, and a rectifying-and-filtering circuit operable to obtain a direct current voltage output from the alternating current signal. The power factor correcting unit includes a voltage booster, an active power factor correcting chip circuit and two transistor control circuits. The resonant converting unit includes a power switch circuit, a resonant chip circuit, and a voltage converting circuit. The voltage converting circuit has primary and secondary windings. The synchronous rectifying unit includes first and second resonant bridge rectifier circuits and a supply voltage output circuit.

Abstract: A switching regulator related to aspects of the invention can include an auxiliary winding for monitoring the voltage across the primary winding of a transformer, a differentiation detecting circuit that detects the timing of reversal start or reversal end of the signal detected by the auxiliary winding and a dead time adjusting circuit that receives a signal to trigger turn OFF of a switch or a switch and, after passing a predetermined delay time from the detection of the signal, generates a signal to trigger turn ON of the switch or the switch. The differentiation detecting circuit can confirm current transfer between body diodes. The dead time adjusting circuit can adjust a dead time to deliver the signal after a predetermined time from the confirmation of the current transfer. In some aspects of the invention, occurrence of hard switching and short-circuit current can be suppressed.

Abstract: A plurality of power supply circuits Z1? are provided according to a load capacity. The power supply circuits Z1? have sides connected in parallel on the side of a direct current input Vi and have sides connected in series on the sides of alternating current outputs Ao. A rectifying circuit DC1 is connected via a resonance circuit Z2 across a combined output of the serially connected sides of the power supply circuits Z1? on the sides of the alternating current outputs Ao. Switching frequencies are simultaneously controlled by a single control signal outputted from a control circuit S1 based on a direct current output voltage detected from the rectifying circuit DC1 through a detection resistor R5.

Abstract: A multi-input bidirectional DC-DC converter with a high voltage conversion ratio is provided. The multi-input bidirectional DC-DC converter with a high voltage conversion ratio implements phase control loops independent from one another so as to realize independent control of charge and discharge in a plurality of energy storage modules, and thus a failure in one of energy storage modules does not affect the other energy storage modules. In addition, it is possible to easily add or remove a control loop that is controlled independently from other control loops.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: A control device for a resonant converter is described. The converter comprises a switching circuit adapted to drive a resonant circuit that includes at least one capacitor. The converter is adapted to convert an input signal into an output signal and the switching circuit includes at least a half bridge of first and second switches, the central point of said half bridge being connected to the resonant circuit. The control device comprises a controller adapted to generate at least a control signal of the switching circuit by comparing a signal representative of the energy of the resonant circuit with at least another signal.

Abstract: An apparatus, system, and method are disclosed for a single stage hybrid charge pump. A switch module is connected to ground. An inductance module is connected between a DC voltage source and the switch module. A first capacitance module is connected to the switch and to the inductance module. A first current blocking module is connected between the DC voltage source the first capacitance module. A second capacitance module is connected to ground. A second current blocking module is connected to a node between the first capacitance module and the first current blocking module and is also connected to the second current blocking module. The switch module is operated to switch between an open state and a closed state thereby causing a voltage across the second current blocking module to increase until it is limited by a voltage limiting module.

Abstract: A method of operating a resonant power converter(1, 2), having a high side switch(3) and a low side switch(4), is disclosed in which the switching is controlled to allow for improved operation at low power levels. The method involved an interruption to the part of the switching cycle in which the low side switch (4) is normally closed, by opening the switch at a particular moment in the cycle which allows the energy to be store in the resonance capacitor (5). Since, as a result, the energy is largely not resonating but stored in a single component, the time quantization of the mode of operation is significantly reduced or eliminated.

Abstract: A burst mode resonant power converter with high conversion efficiency has a rectifier, a power factor correction circuit, a resonant circuit, a controller, and a burst mode triggering unit. The maximum frequency switching end of the controller is connected to a maximum frequency variable circuit. When the load is medium or heavy, the maximum frequency variable circuit increases the maximum switch frequency of the controller. When the load is in the no-load or the light conditions, it reduces the maximum switch frequency thereof. Therefore, the controller reduces the number of times that the resonant circuit switches the bridge switch circuit. The conduction cycle of the 50% pulse signal output to the bridge switch circuit becomes longer. Larger energy can be transmitted at a time to the secondary coil of the transformer. This increases the overall efficiency.

Abstract: A power converter is provided, which may include_a transformer having primary and secondary windings; a primary side switching bridge arrangement including at least two switches switcheable at a switching frequency to drive the primary winding of said transformer, said primary side switching bridge arrangement including at least one decoupling capacitor; and a secondary side rectifying and filtering stage coupled to the secondary winding of said transformer, wherein said secondary side rectifying and filtering stage includes a current doubler with at least one inductor, wherein said at least one decoupling capacitor and said at least one inductor in said current doubler comprise a resonant tank circuit having a resonant frequency range encompassing said switching frequency, whereby said converter exhibits a gain defined by the position of said switching frequency within said resonant frequency range.

Abstract: A control circuit performs at least one of detecting whether the resonance current detected by the current detection unit is beyond a first detection level over a predetermined time period, and detecting, when detecting that the resonance current is beyond the first detection level over the predetermined time period, that the resonance current falls below a second detection level, and detecting whether the resonance current detected by the current detection unit is below a first detection level over a predetermined time period, and detecting, when detecting that the resonance current is below the first detection level over the predetermined time period, that the resonance current exceeds a second detection level, and inverts, when detecting that the resonance current falls below or exceeds the second detection level, the levels of the drive control signal at which the first switching element and the second switching element are turned on or off.

Abstract: The present disclosure relates to a resonant circuit (20). The resonant circuit comprises three resonant circuit input nodes (11, 12, 13) and three resonant circuit output nodes (21, 22, 23), a transformer device and resonant tank devices. The transformer device (TR) comprises three primary windings (LP1, LP2, LP3) and three secondary windings (LS1, LS2, LS3) magnetically connected to each other, where the three secondary windings (LS1, LS2, LS3) are connected to the three resonant circuit output nodes (21, 22, 23). The first, second and third resonant tank devices (RT1, RT2, RT3) are each connected between the respective three resonant circuit input nodes (11, 12, 13) and the respective primary windings (LP1, LP2, LP3). The disclosure also relates to a resonant DC-DC converter comprising such a resonant circuit (20).

Abstract: A maximize efficiency method for resonant converter with self-adjusting switching points is disclosed. The method is operated by a resonant converter, which comprises a transformer and a field effect transistor (FET). When the transistor is turned on, energy is stored in the transformer. When the transistor is turned off, a resonant signal is generated at a drain of the transistor. At this time, a suitable trigger time has to be found to turn on the transistor, so as to reduce switching power loss. The method measures the slope of the resonant signal at the trigger time. This is used as a reference to adjust the next cycle's trigger time. If the slope is negative at the time of trigger, a delta time is added to the trigger time in the next cycle, If the slope is positive, a delta time is subtracted from the trigger time for the next cycle.

Abstract: A switching power source apparatus has a pulse generator of a first pulse. A first resonant series circuit receives the first pulse signal and passes a current having a 90-degree phase delay with respect to the first pulse signal. The current of the first resonant series circuit turns on/off a switching element Q21. A second resonant series circuit receives the second pulse signal and passes a current having a 90-degree phase delay with respect to the second pulse signal. The current of the second resonant series circuit turns on/off a switching element Q22. The pulse generator has a third transformer T3 that has secondary windings to output the first and second pulse signals according to a voltage that is applied to the third transformer and is synchronized with drive signals for the switching elements Q11 and Q12.

Abstract: A resonant mode converter includes a PFC power converter having an input coupled to receive an input voltage. An LLC power converter is cascaded with the PFC power converter. The LLC power converter includes a transformer coupled to generate an output of the resonant mode converter. A feedback circuit is coupled to generate a first current representative of the output of the resonant mode converter. A control unit includes a current limiting circuit coupled to receive the first current and a second current generated in response to a reference voltage. The current limiting circuit is coupled to limit the first current in response to the second current. The control unit further includes an oscillator coupled to generate a control signal having a control frequency in response to the first current. The resonant mode converter output is controlled in response to the control frequency.

Abstract: A flyback converter utilizes a boost inductor coupled between a source of AC power and a synchronous rectifier to provide power factor correction. The synchronous rectifier includes four field-effect transistors configured in a bridge arrangement. Control circuitry controls the on/off states of opposite pairs of the FETs to provide synchronous rectification of the AC power. A primary winding of the flyback transformer is coupled in series with a storage capacitor across the output of the synchronous rectifier. A circuit, which includes a switching transistor, is also coupled across the output of the synchronous rectifier to provide a low resistance path when the switch is closed. The cores of the boost inductor and the transformer are loaded with energy when the switch is closed. When the switch opens, the energy stored in the magnetic cores is transferred to the output via the transformer secondary winding and rectification circuitry.

Abstract: A system includes a load and a single-ended primary-inductance converter (SEPIC) power converter configured to provide power to the load. The SEPIC power converter includes a primary side and a secondary side that are electrically isolated by a transformer. The transformer includes a primary coil and a secondary coil. The primary side includes (i) a capacitor coupled to a first end of the primary coil and (ii) an inductor and a switch coupled to a second end of the primary coil. The primary side of the SEPIC power converter could also include a diode coupled between the inductor and the switch, where the diode is coupled to the second end of the primary coil. The capacitor could be configured to transfer energy to the secondary side of the SEPIC power converter through the transformer during valleys associated with a rectified input voltage.

Abstract: A control circuit for a resonant power converter and a control method thereof are disclosed. The control circuit comprises a first transistor and a second transistor switching a transformer through a resonant tank. A controller receives a feedback signal for generating a first switching signal and a second switching signal coupled to drive the first transistor and the second transistor respectively. The feedback signal is correlated to an output of the resonant power converter. A diode is coupled to the second transistor for detecting the state of the second transistor for the controller. The first switching signal and the second switching signal are modulated to achieve a zero voltage switching (ZVS) for the second transistor.

Abstract: The configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

Abstract: A resonant converter includes first and second input terminals for applying an input voltage and first and second output terminals for providing an output voltage. A transformer includes a primary winding and a secondary winding, where both the primary winding and the secondary winding have a first and a second terminal. A series resonant circuit includes a capacitive element and the primary winding of the transformer. A switching circuit is connected between the input terminals and the series resonant circuit. A rectifier circuit is connected between the secondary winding and the output terminals. A clamping circuit is connected between one of the first and second terminals of the primary winding and the input terminals.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: One embodiment relates to an LLC resonant power converter system. The system includes a transformer comprising a primary inductor and a secondary inductor and a switch control stage configured to generate a plurality of switching signals having a duty-cycle. The system also includes an input stage comprising the primary inductor and a plurality of switches that are controlled in response to the respective plurality of switching signals to generate a primary resonant current and an output stage comprising the secondary inductor and being configured to conduct an output current through a load based on a secondary resonant current to generate an output voltage. The system further includes a controller configured to limit a magnitude of the output current to a predetermined magnitude in response to variations of the load.

Abstract: A non-isolated resonant converter is provided. The provided non-isolated resonant converter includes a switch circuit, a resonant circuit and a rectifying-filtering circuit. The switch circuit, the resonant circuit and the rectifying-filtering circuit are sequentially connected. The resonant circuit includes an auto-transformer, a capacitor and an inductor, wherein the capacitor and the inductor are connected to the auto-transformer. The configuration of the provided non-isolated resonant converter has small size, low loss and high power density.

Abstract: A DC-DC converter (1) is provided having a resonant half-bridge circuit (2) and a transformer (TX1) that has a primary winding (P1) and a secondary winding (S1, S2) on a transformer core (4). The voltage converter (1) has a secondary circuit (3) with which the secondary winding (S1, S2) is associated and a switch (Q3, Q4) that is connected in series to the secondary winding (S1, S2), and a smoothing capacitor (C0, C01). The switch (Q3, Q4) is operated as a synchronous rectifier.

Abstract: A control circuit of a resonant power converter is disclosed. The control circuit comprises a first transistor and a second transistor for switching a transformer and a resonant tank comprising a capacitor and an inductor. A controller is configured to receive a feedback signal correlated to the output of the power converter for generating a first switching signal and a second switching signal to drive the first transistor and the second transistor, respectively. A diode coupled to the first transistor and the resonant tank for detecting the state of the first transistor and generating a detection signal for the controller. The detection signal indicates if the transistors are in a zero voltage switching (ZVS) state. If the transistors are not in the ZVS state, the switching frequency of the transistors will be increased.

Abstract: During a soft start period at the time of startup, a PWM control is carried out. After the soft start period ends, the PWM control is converted into a frequency control, so that stress of a switching element is suppressed and the audible oscillation frequency is removed. As a result, it is possible to obtain a switching power supply device having high power conversion efficiency.

Abstract: The present invention relates to multi-phase parallel-interleaved converter circuits with each phase having two or more transformers and two or more rectifiers electrically coupled to the two or more transformers, and layouts of the transformers and the rectifiers of the multi-phase parallel-interleaved converter circuits. In the layouts, the multiple transformers and the multiple rectifiers of the multi-phase converters are interleavingly arranged to be symmetrical to common output polarized capacitor(s) so as to ensure the rectifier outputs of each phase relative to the common output polarized capacitors is symmetrical, thereby reducing the output ripples of the current of the output capacitors.