165results about How to "Improve light load efficiency" patented technology

The invention relates to a DC-DC power supply conversion device, in particular to a zero-voltage switch (ZVS) flyback-type DC-DC power supply conversion device with efficient conversion, efficient light-load conversion and low standby power consumption. An auxiliary switch and an absorption capacitor are additionally arranged on the flyback circuit; the auxiliary switch and the absorption capacitor are connected in series so as to form an auxiliary branch circuit; the auxiliary branch circuit can be connected in parallel to the two ends of the primary winding of a transformer or alternatively connected in parallel to the two ends of a primary-side switch; and the auxiliary switch is conductive for a determined period of time before the primary-side switch is conductive. Compared with the prior art, the energy of the circuit leakage inductor can be absorbed and transferred to the output terminal and a soft switch for realizing the primary-side switch, so that the invention can greatly improve the circuit efficiency; the parasitic oscillation caused by the leakage inductor can be suppressed, so that the EMI (electromagnetic interference) characteristics of the circuit can be improved; and the circuit can be controlled more easily, thereby improving the light-load circuit efficiency and reducing the idle-load energy loss.

The configuration of a synchronous rectification circuit and a controlling method thereof are provided. The proposed circuit includes a converter including a first switch and a first synchronous rectifier, and a burst mode controller including a logic process module performing one of functions of delaying one of a non-integer and at least one operating periods to generate a synchronous rectification driving signal of the first synchronous rectifier counting from a beginning of a first pulse of a driving signal of the first switch during a working time of a burst period, and turning off the synchronous rectification driving signal of the first synchronous rectifier by one of the non-integer operating period and the at least one operating period ahead of an ending of a last operating period of the driving signal of the first switch during the working time of the burst period.

The present invention discloses a voltage mode switching regulator with improved light load efficiency and mode transition characteristic, and a control circuit and a control method therefor. The switching regulator can switch between a pulse width modulation (PWM) mode and a pulse skipping mode. The control method for the switching regulator comprises: comparing a feedback signal relating to an output voltage with a reference signal, to generate an error amplification signal; generating a duty signal according to the error amplification signal and a ramp signal, to control the switching regulator; setting a threshold level of the error amplification signal and a threshold level of the pulse skipping mode according to the error amplification signal in a stable status; and when the error amplification signal is close or equal to the threshold level of the pulse skipping mode, generating a pulse skip signal to enter the pulse skipping mode.

A buck-boost switching regulator which includes a first switch, a first diode, an inductor, a second switch, a second diode, and a controller for controlling the first switch and the second switch, the controller being configured to receive a current signal indicative of a inductor current flowing in the inductor, and generating a signal indicative of an average current flowing in the inductor, the average current being utilized to control the first switch and the second switch, wherein the controller includes a first compensator circuit for outputting a voltage error signal, a second compensator circuit for outputting a current error signal and a modulator circuit to output a first control signal to control the first switch and a second control switch to control the second switch.

The invention provides an asymmetric half-bridge flyback converter and a driving control method therefor. A load detection circuit detects a load signal of the asymmetric half-bridge flyback converter, compares the load signal with a set load point, forms a feedback signal by the comparison result, and outputs the feedback signal to a driving control module and a main control chip concurrently; the main control chip outputs a PWM signal to a driving circuit; the driving circuit outputs two paths of signals, namely, a main switching tube driving signal and a driving voltage signal; the main switching tube driving signal drives the switch on and switch off of a main switching tube; the driving voltage signal is input to the driving control module; and after the driving control module receives the driving voltage signal and the feedback signal, a first driving signal or a second driving signal is output to control the switch on or switch off of a clamping switching tube. The control method and the control circuit are simple and reliable, easy to realize, capable of solving the problems of high loss in light load output and no load of the asymmetric half-bridge flyback converter, and capable of improving the light load efficiency.

The invention in particular relates to a flyback active-clamp, asymmetrical half-bridge switching converter control circuit and control method. According to the technical scheme of the circuit, a flyback control circuit is provided and controls an integrated control circuit controlling a switch tube and a clamping tube. The integrated control circuit comprises a driving unit of the switch tube, a driving unit of the clamping tube, and a turn-off holding driving unit. When the load is light or zero, the total of a turn-on time of the switch tube, a turn-on time of the clamping tube and a dead zone therebetween forms a single period. The time length of the single period is a fixed value. The turn-on time of the switch tube and that of the clamping tube are in a complementary relation in the single period. The time of the single period and a turn-off holding time form a total working period. Compared with the prior art, while ensuring the efficiency of a conventional circuit and the EMI advantage under a load no less than a light load, the circuit improves the light load efficiency and reduces the zero load power consumption.

The present invention relates to a control circuit and a control method of a synchronous rectifier. In a preferred embodiment according to the invention, the synchronous rectifier control circuit comprises the following components: (1) a first detection circuit which is used for detecting a voltage between a first power terminal and a second power terminal before the device is switched on and generating a first control signal for regulating the switching-on time of the synchronous rectifier; (2) a second detection circuit which is used for detecting a voltage between the first power terminal and the second power terminal after the device is switched off and generating a second control signal for regulating the switching-off time of the device; and (3) a driving control circuit which receives the first control signal and the second control signal and generating a grid control signal for driving a control terminal of the synchronous rectifier.

The invention provides a light load control method and device of an LLC (Liquid Level Control) resonant converter, belongs to the field of power conversion, and solves the problem that soft switching environments of a zero-voltage switch and a zero-current switch are lost. The method comprises the following steps of: A, judging whether the device works at a light load state or not; B, when the device does not work at the light load state, carrying out frequency adjusting control mode; C, when the device works at the light load state, carrying out fixed frequency pulse width control mode; and D, outputting a control signal of a corresponding switching tube. The device comprises a controller, a frequency modulation module and a width modulation module, a current detection unit and a voltage detection unit, wherein the controller is connected with a feedback compensating error amplifier; the voltage detection unit is connected with the feedback compensating error amplifier; the current detection unit is connected with the controller; the controller is connected with a working module switching unit; the frequency modulation module and the width modulation module are respectively connected with the controller and the working mode switching unit; and the working module switching unit is connected with the switching tube. The device and the method realize optimization of the soft switching environments and resonance parameters in a full-load range.

The invention discloses a method for enhancing the non-uniform variation grid width of the light load efficiency of an integrated switch DC-DC converter, a Buck-Boost converter in the invention adopts the design of a CSMC 0.5mu m CMOS process library, whole-circuit integration is realized except for a passive filter, the external filter inductance is 2.2mu H, and the filter capacitance is 1mu F. According to the requirements of input voltage and output voltage, the converter can work in three modes: Buck (voltage reducing), Buck-Boost (voltage reducing and boosting) and Boost (voltage boosting), the range of the input voltage is 2.5V-4.2V, the range of the output voltage is 1.5V-5V, and the working frequency is 5MHz. A non-uniform grid width modulation method is adopted in the whole load current range of 10mA-650mA. When the converter works at high frequency of 5MHz, the efficiencies of medium load and heavy load keep above 90 percent all the time, and the efficiency of light load (10mA) can reach above 80 percent. As the grid width of a switching tube is only changed and a control link of the working efficiency of an extra switching tube is not adopted, negative effects caused by frequency conversion control are eliminated fundamentally.

The invention discloses a pulse hopping mode PSM control method suitable for a primary side feed-back fly-back converter. The method comprises the following steps: indirectly sampling output voltage through an auxiliary winding; outputting the value of the output voltage through a comparison module; selecting a proper duration hopping mode from a duration hopping control module by adding the judgment of a peak current module and a duration hopping calculation module; finally, outputting a proper duty cycle through a DPWM module to drive a switch MOS transistor and control the voltage-stabilized output of digital power. Through the adoption of the method, on one hand, the light load efficiency can be high by switching off a part of circuit modules of a system in a part of switch duration; on the other hand, compared with the conventional PFM control method, the pulse hopping mode PSM control method has the advantages that PSM control is simpler, filtering can be easier due to a controllable frequency range, and the EMI can be reduced effectively.

A feedback circuit for an isolated power converter includes an opto-coupler and a reversed polarity regulator. The opto-coupler provides a current related to an output voltage of the isolated power converter. When the isolated power converter enters light load, the output voltage rises and the reversed polarity regulator reduces the current to decrease the power consumption and thus improve the light load efficiency of the isolated power converter.

The invention provides a controller for a non-complementary active clamp flyback converter. The controller comprises a frequency control unit, a pulse width control unit, a sequential control unit anda driving unit, uses a multi-mode control mode, and further comprises a wave peak detecting unit and a mode a determining unit. The wave peak detecting unit detects the peaks of an oscillating voltage at the drain end of a main switching tube, and turns on a clamp tube at the troughs in the non-complementary mode of the converter. The turning off of the clamp tube is determined by internally setturn-on time. The mode determining unit, according to feedback voltage FB, gives a mode switching signal to the sequential control unit according to a mode determining result signal. By using a DCM mode, the controller prevents the clamp tube from being turned on, reduces the peak-to-peak value of the excitation current when entering a frequency hopping mode, avoids audio noise, and optimizes no-load power consumption. Since the comparison process of the mode conversion is provided with a long time delay, the influence of mode switching on a converter control loop is reduced.

The invention relates to the field of switch converters and aims to provide a control method of an asymmetrical half-bridge fly-back converter. According to the control method of the asymmetrical half-bridge fly-back converter, the efficiencies of both light loading and heavy loading can be considered, in the light loading, the duty ratio can be reduced, the primary side peak current is reduced, the circulation energy is reduced, the frequency converting control can also be achieved, and the no-load power consumption and the light-load loss are effectively reduced; in the heavy loading, the complementation can be achieved, a part of the energy is delivered through a blocking capacitor to the greatest extent, the energy stored by a transformer is reduced, in addition, two switches achieve zero voltage switching, and the efficiency of the converter is improved.

The invention discloses an asymmetric half-bridge converter and a control method thereof. A one-way clamping network is additionally arranged and is connected in parallel with a primary side, a secondary side or a third winding of a transformer, an auxiliary switch is controlled to be switched off when an excitation inductance current reaches a set value, the one-way clamping network is conducted,a clamping current passes through the one-way clamping network, the clamping current is clamped and maintained to be basically unchanged by the one-way clamping network, the one-way clamping networkis controlled to be switched off within a certain time before a main switch is conducted, the clamping current is released, voltages of two ends of the main switch are reduced to zero or be approximate to zero, and zero-voltage conduction of the main switch is achieved. By the asymmetric half-bridge converter, effective control of negative peak of the excitation inductance current can be achieved,a current effective value of a power device under light load of a converter is reduced, the light-load efficiency of the converter is substantially reduced under the condition that the advantages ofzero-voltage conduction of an existing technical scheme is maintained, the no-load loss is reduced, and control implementation is simple and efficient.

An isolated power converter, an inverting type shunt regulator, and an operating method thereof are disclosed. The isolated power converter includes a transformer, an inverting type shunt regulator, a controller, and an optocoupler. The inverting type shunt regulator is located on the secondary side of the transformer. The inverting type shunt regulator includes an error amplifier and a MOSFET. The controller is located on the primary side of the transformer. The controller includes an inverting unit cooperated with the MOSFET. The controller receives a feedback voltage. The optocoupler is coupled to the inverting type shunt regulator and the controller to provide an opto-coupling current to the controller.

A DC-to-DC converter comprises an error amplifier, a comparator, a PWM controller, a power switch unit, and a control signal monitoring circuit. The PWM controller receives a comparison signal from the comparator and generates a digital control signal that controls the power switch unit such that the DC-to-DC converter supplies a regulated voltage onto a load. The control signal monitoring circuit monitors the digital control signal and detects either a heavy load or a light load condition based on characteristics of the digital control signal. Under the light load condition, the monitoring circuit generates a first enabling signal such that the DC-to-DC controller operates in a power-save mode. Under the heavy load condition, the monitoring circuit generates a second enabling signal such that the DC-to-DC controller operates in a normal operation mode. The DC-to-DC converter consumes substantially less power in the power-save mode than in the normal operation mode.

The invention provides an interleaved parallel magnetic-integration bidirectional full-bridge LLC resonant converter and relates to the technical field of power and electronic applications. The interleaved magnetic-integration bidirectional full-bridge LLC resonant converter comprises two paths of an interleaved parallel bidirectional full-bridge LLC resonant converter. The first path of the bidirectional full-bridge LLC resonant converter comprises a first primary-side circuit, a first secondary-side circuit, a resonant transformer and a magnetic inductor thereof. The second path of the bidirectional full-bridge LLC resonant converter comprises a second primary-side circuit, a second secondary-side circuit, a resonant transformer and a magnetic inductor thereof. The primary-side circuit and the secondary-side circuit of each path of the bidirectional full-bridge LLC resonant converter are respectively in the form of a full-bridge LLC resonant circuit and are used for realizing the bidirectional energy flow. The two resonant transformers, the magnetic inductors thereof and four resonant inductors of the two paths of the interleaved parallel bidirectional full-bridge LLC resonant converter are magnetically integrated through integrated magnetic pieces. According to the technical scheme of the invention, the large-power, high-transformation-ratio, small-volume, bidirectional and high-efficiency operation of the electric energy is realized.

The invention relates to a DC-DC power supply conversion device, in particular to a zero-voltage switch (ZVS) flyback-type DC-DC power supply conversion device with efficient conversion, efficient light-load conversion and low standby power consumption. An auxiliary switch and an absorption capacitor are additionally arranged on the flyback circuit; the auxiliary switch and the absorption capacitor are connected in series so as to form an auxiliary branch circuit; the auxiliary branch circuit can be connected in parallel to the two ends of the primary winding of a transformer or alternativelyconnected in parallel to the two ends of a primary-side switch; and the auxiliary switch is conductive for a determined period of time before the primary-side switch is conductive. Compared with the prior art, the energy of the circuit leakage inductor can be absorbed and transferred to the output terminal and a soft switch for realizing the primary-side switch, so that the invention can greatly improve the circuit efficiency; the parasitic oscillation caused by the leakage inductor can be suppressed, so that the EMI (electromagnetic interference) characteristics of the circuit can be improved; and the circuit can be controlled more easily, thereby improving the light-load circuit efficiency and reducing the idle-load energy loss.

The configuration of a synchronous rectification circuit and a controlling method thereof are provided. The proposed circuit includes a converter including a first switch and a first synchronous rectifier, and a burst mode controller including a logic process module performing one of functions of delaying one of a non-integer and at least one operating periods to generate a synchronous rectification driving signal of the first synchronous rectifier counting from a beginning of a first pulse of a driving signal of the first switch during a working time of a burst period, and turning off the synchronous rectification driving signal of the first synchronous rectifier by one of the non-integer operating period and the at least one operating period ahead of an ending of a last operating period of the driving signal of the first switch during the working time of the burst period.

The invention discloses a drive control circuit for shunt-wound synchronous rectification tubes, which is used for driving and controlling the N shunt-wound synchronous rectification tubes, wherein N is a positive integer. The drive control circuit has an input end and M output ends, wherein the input end is used for acquiring a load current signal; the M output ends are used for outputting driving signals; M is the positive integer more than or equal to N; the M output ends are connected with drive electrodes of the N synchronous rectification tubes; the drive electrode of each synchronous rectification tube is connected with one output end; each output end is connected with the drive electrode of at least one synchronous rectification tube; and the drive control circuit controls the number of switched-on synchronous rectification tubes of the N shunt-wound synchronous rectification tubes according to the magnitude of the load current signal. The embodiment of the invention also provides a corresponding switching power supply. The drive control circuit provided by the embodiment of the invention can adaptively adjust the number of the switched-on synchronous rectification tubes according to the change of a load, thereby satisfying application needs, reducing the drive loss under low-load condition and improve light load efficiency.

The invention discloses a grid-connected photovoltaic inverter device and a control method for improving conversion efficiency thereof and belongs to the field of inverter control. The device comprises N grid-connected photovoltaic inverters, wherein a voltage outer loop control circuit (3) of each grid-connected photovoltaic inverter comprises a bus voltage sampling circuit (301), first and second bus voltage regulators (302 and 303), first and second amplitude limiting circuits (304 and 305) and three voltage loops. The control method comprises that: given voltage in different grades is respectively set for the bus voltage regulators of the plurality of grid-connected inverters; along with the increase of the input power, the inverters work in turn according to the given voltage, and the light load efficiency is improved by reducing the number of the operating inverters under the condition of light load; and different set values and output amplitude limiting values are applied to a linear bus voltage regulator of a single grid-connected inverter so as to ensure that the inverters can operate at the highest efficiency preferentially under different power grades, and the overall efficiency of the system is improved.

The invention discloses a working size switching circuit for power transistors in a DC-DC converter, mainly solving the problem of difficulty in reaching high efficiency by the traditional DC-DC converter when in a low load state. The working size switching circuit comprises a pulse width modulation (PWM) comparing module, a first drive module, a first pair of power MOS (Metal Oxide Semiconductor) transistors, a hysteresis comparing module, a second drive module and a second pair of power MOS transistors, wherein the PWM comparing module controls the first pair of power MOS transistors to work through the first drive module; the hysteresis comparing module compares a load current with a switching threshold current to generate a judging signal and controls that the second pair of power MOS transistors does not work when the load current is lower than the switching threshold current through the second drive module and the second pair of power MOS transistors works when the load current is more than the switching threshold current, so that actually working power transistors of the DC-DC converter are different in quantity under same load conditions, and the working size of the power transistors are switched. According to the working size switching circuit, the efficiency of the DC-DC converter when in the light load state can be increased, and load currents corresponding to the switching of the working sizes of the power transistors are constant under various working duty ratios.

A MOSgated device has spaced vertical trenches lined with a gate oxide and filled with a P type polysilicon gate. The gate oxide extends along a vertical N− channel region disposed between an N+ source region and an N− drift region. A Schottky barrier of aluminum is disposed adjacent the accumulation region extending along the trench to collect holes which are otherwise injected into the source region during voltage blocking. A common source or drain contact is connected to the N+ region and to the Schottky contact. A two gate embodiment is disclosed in which separately energized gates are connected to alternatively located gate polysilicon volumes.

The invention discloses an LLC resonance power converter with double resonance frequencies. On the basis of the traditional LLC resonance power converter resonance network formed by two bridge arms and four NMOS transistors M3, M4, M5 and M6, a bridge arm formed by NMOS transistors M1 and M2 is additionally arranged, an active network is formed together with an inductor La, an isolation transformer and a Class D full bridge rectifier are serially connected sequentially, the Class D full bridge rectifier is sequentially connected with a sampling circuit, an error amplification circuit, an STM32F407 microcontroller and a high-frequency gate driving circuit via a load R, and output of the high-frequency gate driving circuit drives three bridge arms and six MOS transistors from M1 to M6 in the resonance network additionally provided with the active network to work normally. The LLC resonance power converter with double resonance frequencies has two working modes, the light-load efficiency of the LLC resonance converter is greatly improved, a switching frequency range is narrow, and symmetric work in a full load range is realized.

The invention discloses an adaptive drive method for synchronous rectification of a flyback converter. The method includes the steps of 1, composing a secondary side current detection circuit, a current zero-cross detection circuit, an AND gate logic circuit, an isolating circuit, a drive circuit and a reverse circuit into a secondary side drive circuit; 2, determining a drive signal of a secondary side synchronous rectifier tube according to the output of the AND gate logic circuit; 3, using input of the AND gate logic circuit as an output value of a primary side PWM drive reverse signal and circuit zero-cross detection circuit. The method is applied to implementation of adaptive drive signals of synchronous rectifier tubes for the flyback converter using synchronous rectification and has the advantages that the method can effectively adapt to defects such as low efficiency, high no-load loss and difficulty in loop stabilization during light loading, and efficient, stable operation of the circuit is achieved.

The invention provides a synchronous buck DC-DC converter capable of achieving low output ripples in times of underloading. A frequency-down circuit is additionally arranged on the structural basis of the synchronous buck DC-DC converter, and accordingly the problem of being large in output ripple in times of underloading is mainly solved. The frequency-down circuit comprises a transconductance amplifier and a clock circuit. The transconductance amplifier is used for detecting whether the output end of the DC-DC converter is underloaded or not, the clock circuit lowers the frequency of clock signals CLK in times of underloading, and the output ripples in times of underloading are greatly reduced while a feedback circuit has enough time to adjust input power so as to be adapted to change of output loads and to improve underloading efficiency of the converter. The application range of the converter is widened, and the performance of the converter is improved.