| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 363210180 | Utilizing pulse-width modulation | 69 |
| 20080259655 | SWITCHING-MODE POWER CONVERTER AND PULSE-WIDTH-MODULATION CONTROL CIRCUIT WITH PRIMARY-SIDE FEEDBACK CONTROL - A pulse-width-modulation control circuit of a switching-mode power converter with a primary-side feedback control is disclosed. The switching-mode power converter includes a transformer, a power switch, a current sensing resistor and the pulse-width-modulation control circuit. The transformer includes a primary-side winding, a secondary-side winding and an auxiliary winding. The pulse-width-modulation control circuit includes a sample and hold circuit, a transconductor circuit, an error amplifier and a pulse-width-modulation generator. | 10-23-2008 |
| 20080259656 | Regulating output current from a primary side power converter by clamping an error signal - An inductor current flows through an inductor of a flyback converter. In a constant voltage mode, the pulse width of an inductor switch control signal is adjusted to maintain a constant output voltage of the flyback converter. The inductor switch control signal controls a switch through which the inductor current flows. In a constant current mode, a comparing circuit, a control loop and a clamp generator circuit are used to maintain the peak level of inductor current. The comparing circuit generates a timing signal based on the ramp-up rate of the inductor current. The control loop uses the timing signal and a feedback signal to generate a time error signal. The clamp generator circuit uses the time error signal to generate a clamp signal that adjusts the pulse width of the inductor switch control signal to clamp the peak current output by the flyback converter in the constant current mode. | 10-23-2008 |
| 20080278974 | QUASI-RESONANT FLY-BACK CONVERTER WITHOUT AUXILIARY WINDING - Disclosed is a switching converter without an auxiliary winding. The switching converter has a transformer, a switching transistor, a coupling circuit and a regulating circuit. The transformer has a primary winding and a secondary winding, and is for transforming an input voltage into an output voltage; a first end of the switching transistor is coupled to the primary winding of the transformer, and the switching transistor is for controlling an operation of the transformer according to a control signal; the coupling circuit is for coupling a signal at the first end of the switching transistor to generate a coupled signal; and the regulating circuit is for detecting the coupled signal to generate the control signal according to the detecting result. | 11-13-2008 |
| 20080278975 | Switched Mode Power Converter and Method of Operation Thereof - The invention relates to a switched mode power converter and a method of operating such a converter A switched mode power converter according to the invention includes a transformer ( | 11-13-2008 |
| 20080304294 | Power Supply for Relieving Spikes - In a feedback circuit of a power supply, an electrical level of an output voltage is stabilized corresponding to changes of an electrical level of a pulse width modulation signal, and effects, which are caused by spikes, on passive elements are decreased to a lowest degree. The electrical level of the output voltage is stabilized by storing a voltage corresponding to a low-to-high electrical level of the PWM signal with a capacitor, by discharging the stored voltage with a high-to-low electrical level of said PWM signal, and by regulating a discharging path of the stored voltage with a diode, which is not conducted. The abovementioned disposition may be utilized on various power-consuming devices, a duty cycle of each of which is controlled with a PWM signal, for stabilizing output voltages of said power-consuming devices, and for reducing effects, which are caused by spikes, on passive elements inside said power-consuming devices. | 12-11-2008 |
| 20080304295 | Switching Power Converter with a Secondary-Side Control - This invention discloses a power converter with a secondary-side control, including an input circuit with one or more switches, an output circuit with an output end and a controller, and a transformer with a primary-side coil assembly connecting the switch(es) and a secondary-side coil assembly connecting the output circuit. The on/off state of the switch(es) is controlled by variations in voltage of primary-side coil assembly. The controller in the output circuit detects an output voltage and sends detected results to the primary-side coil assembly as a feedback for primary-side coil assembly to regulate the PWM or PFM action of the switch in a specific way to maintain voltage stability. | 12-11-2008 |
| 20080310193 | PWM Controller for Compensating a Maximum Output Power of a Power Converter - A PWM controller having an oscillator, a control circuit and a two-level limiter is provided. The oscillator generates a pulse signal. The control circuit couples to the oscillator for generating a PWM signal in response to the pulse signal, wherein the PWM signal controls a power switch. The two-level limiter couples to the control circuit for generating a two-level limit signal in response to an on-time of the PWM signal, wherein the two-level limit signal is formed by a first-level signal and a second-level signal during a switching period of the PWM signal, and the first-level signal is used to limit the maximum output power of the power converter under a high-line input voltage with a heavy-load condition, and the second-level signal is used to limit the maximum output power of the power converter under a low-line input voltage with the heavy-load condition. | 12-18-2008 |
| 20080310194 | Method and apparatus for improving the light load efficiency of a switching mode converter - A method and apparatus are provided for a switching mode converter to improve the light load efficiency thereof. The converter is thus operated with three modes by monitoring a feedback signal and a supply voltage. When the feedback signal indicates that loading gets light enough, the converter is switched from the first mode to the second mode, and during the second mode some cycles are skipped. If loading is too light, the converter is switched from the second mode to the third mode, and during the third mode more cycles will be skipped. | 12-18-2008 |
| 20090097281 | LEAKAGE-INDUCTANCE ENERGY RECYCLING CIRCUIT AND FLYBACK CONVERTER WITH LEAKAGE-INDUCTANCE ENERGY RECYCLING CIRCUIT - A flyback converter with a leakage-inductance energy recycling circuit includes a transformer and a leakage-inductance energy recycling circuit. The leakage-inductance energy recycling circuit includes a clamping circuit, an energy storage circuit, and a switch connected between the clamping circuit and the energy storage circuit. A power transistor is electrically connected to a primary winding of the transformer. The clamping circuit clamps the voltage of the power transistor at a predetermined voltage. The energy storage circuit stores the leakage-inductance energy of the primary winding. When the switch is turned off, the clamping circuit receives and stores the leakage-inductance energy of the primary winding, so as to clamp the voltage of the power transistor to a predetermined voltage; when the switch is turned on, the energy stored in the clamping circuit is stored in the energy storage circuit through the switch. | 04-16-2009 |
| 20090147548 | CONTROL CIRCUIT FOR ADJUSTING LEADING EDGE BLANKING TIME AND POWER CONVERTING SYSTEM USING THE SAME CONTROL CIRCUIT - A control circuit for adjusting leading edge blanking time is disclosed. The control circuit is applied to a power converting system. The control circuit adjusts a leading edge blanking time according to a feedback signal relative to a load connected to the output terminal of the power converting system. An over-current protection mechanism of the power converting system is disabled within the leading edge blanking time. | 06-11-2009 |
| 20100002474 | SWITCH CONTROL DEVICE AND CONVERTER INCLUDING THE SAME - The present invention relates to a switch controller and a converter having the same. The converter according to the present invention includes a power transfer device that transmits input power to an output terminal as output power, a power switch connected to a first end of the power transfer device and that controls power transmission of the power transfer device, and a switch controller that controls switching operation of the power switch. The switch controller receives an output voltage detection signal corresponding to an output voltage according to the power transmitted from the power transfer device, generates a duty control signal corresponding to a difference between the output voltage detection signal and a reference signal for controlling the output voltage, and determines turn-on/off of the power switch by using the duty control signal, and a DC gain of a feedback transfer function between the reference signal and the output voltage has a constant value. | 01-07-2010 |
| 20100008110 | CONTROL CIRCUIT AND METHOD FOR A FLYBACK POWER CONVERTER - A flyback power converter includes a power switch connected to a primary side of a transformer, and a sensing signal is provided for a control circuit to switch the power switch so as for the transformer to convert an input voltage into an output voltage. The sensing signal is a function of the input voltage, and the control circuit extracts a variation of the sensing signal during a preset time period. The variation of the sensing signal is used to prevent the output ripple and the green mode entry point of the flyback power converter from varying with the input voltage. | 01-14-2010 |
| 20100073967 | SWITCHING CONTROL CIRCUIT AND SWITCHING POWER SUPPLY - A switching element controls supply of a primary current to a transformer. A basic signal generator circuit generates a PWM basic signal regardless of a control condition of the switching element. A timer circuit measures an elapsed, predetermined longer time than one cycle of the PWM basic signal since a start of ON control of the switching element. A control circuit ON controls the switching element when receiving the PWM basic signal, and OFF controls the switching element when receiving either one of a first OFF signal based on output feedback of a switching power supply and a second OFF signal based on completion of time measuring by the timer circuit. | 03-25-2010 |
| 20100103705 | SHORT CIRCUIT PROTECTION CIRCUIT FOR A PULSE WIDTH MODULATION (PWM) UNIT - A short circuit protection circuit for a pulse width modulation (PWM) unit which includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit and an internal clock circuit; wherein the UVLO circuit detecting a bias power (Vcc) and delivering an UVLO signal when the bias power is judged excessively low, the PWM unit further comprising: a short circuit detector, a short circuit recovery circuit and a frequency multiplexer. The short circuit detector is to detect the UVLO signal and generate a short signal. The short circuit recovery circuit to set a pre-determined recovery time and generate a recovery signal when the pre-determined recovery time ends. The frequency multiplexer which is triggered by the short signal when the short circuit event occurs to change a switching frequency to a short PWM frequency, and triggered by the recovery signal to restore the switching frequency. | 04-29-2010 |
| 20100110735 | POWER ADAPTER WITH VOLTAGE-STABILIZED COMPENSATION - A power adapter with voltage-stabilized compensation includes a pulse frequency modulation circuit to generate a driving pulse which has a variable OFF time interval to control power transformed and output by a transformer. The power adapter also has an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit includes a time interval modulation unit to receive the feedback signal and a feedback compensation unit. The time interval modulation unit sets a level voltage compared with the feedback signal to generate a sample signal to modulate the OFF time interval. The feedback compensation unit provides a compensation signal to the time interval modulation unit to change the size of the feedback signal or sample signal thereby to compensate the voltage output from the secondary side. | 05-06-2010 |
| 20100172160 | SYSTEM AND METHOD FOR PROVIDING CONTROL FOR SWITCH-MODE POWER SUPPLY - System and method for providing control for switch-mode power supply. According to an embodiment, the present invention provides a system for regulating a power converter. The system comprises a signal processing component that is configured to receive a first voltage and a second voltage, to process information associated with the first voltage and the second voltage, to determine a signal based on at least information associated with the first voltage and the second voltage, and to send the signal to a switch for a power converter. The switch is regulated based on at least information associated with the signal. The signal processing component is further configured to determine the signal to be associated a first mode, if the first voltage is higher than a first threshold. | 07-08-2010 |
| 20100182808 | SWITCHING POWER SOURCE DEVICE - A pseudo-resonant switching power source device is provided which comprises a primary winding | 07-22-2010 |
| 20100188874 | AC - DC CONVERTER - AC-DC converter is provided which comprises an auxiliary winding | 07-29-2010 |
| 20100315844 | Method for Operating a DC-DC Converter - A method of operating a DC-DC converter according to the current mode control is provided. A current measuring signal for determining a turn-off time of a converter switching element is supplied to a PWM controller and a voltage that is proportional to the current measuring signal is compared by a comparator to a reference voltage. When the reference voltage is exceeded, the converter switching element is turned off. | 12-16-2010 |
| 20100321964 | Power Adapter Employing a Power Reducer - A power adapter including a power reducer for no-load or light load applications and method of operating the same. In one embodiment, the power adapter includes a capacitor coupled to an input of the power adapter, and a bleeder switch coupled in parallel with the capacitor. The power adapter also includes a detection circuit configured to sense an ac mains voltage at the input of the power adapter and turn on the bleeder switch upon detection of a loss of the ac mains voltage. In addition to or in lieu of, the power adapter may include a power converter, and a disconnect switch configured to disconnect the ac mains voltage from the power converter in response to a signal from a load. | 12-23-2010 |
| 20110051472 | METHOD AND SYSTEM FOR EFFICIENT POWER CONTROL WITH MULTIPLE MODES - Method and system for efficient power control with multiple modes. According to an embodiment, the present invention provides a power system with selectable power modes. The power system includes a first terminal for outputting energy, and the first terminal is electrically coupled to a load. The system also includes a pulse-frequency modulation (PFM) component that is configured to adjust a pulse frequency based on the load. The system additionally includes a pulse-width modulation (PWM) component that is configured to adjust a pulse width based on the load. The system further includes a switch that is electrically coupled to the first terminal. Also, the system includes a control component, the control component being configured to provide a control signal that is capable of causing the switch to be turned on or off. The control signal is associated with an output of the PWM component and the pulse width if an output is greater than a predetermined value. The control signal is associated with an output of the PFM component and the pulse frequency if an output is lower than a predetermined value. | 03-03-2011 |
| 20110063880 | FORWARD CONVERTER TRANSFORMER SATURATION PREVENTION - A control circuit for use in a power converter in one aspect limits the magnetic flux in a transformer. Controlled current sources produce a first current that is proportional to an input voltage of the power converter and a second current that is proportional to a reset voltage of the transformer. An integrating capacitor is charged with the first current and discharged with the second current, where a voltage on the capacitor is representative of the magnetic flux in the transformer. A logic circuit is adapted to turn off the switch when the voltage on the integrating capacitor is greater than or equal to a first threshold voltage, and to allow the switch to turn on and off in accordance with a pulse width modulation signal after a delay time that begins when the integrating capacitor discharges to a second threshold voltage. | 03-17-2011 |
| 20110075450 | SWITCHING POWER SUPPLY DEVICE - 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. | 03-31-2011 |
| 20110085359 | ADAPTIVE FREQUENCY JITTER FOR CONTROLLER - In order to convert an input power to one or more DC power levels that are provided to an output load, some aspects of the present disclosure relate to techniques for driving a switching regulator as a function of a pulsed voltage signal. In particular, this pulsed voltage signal is provided substantially at a target frequency, but exhibits frequency jitter that causes the pulsed voltage to vary slightly from the target frequency in time. The frequency jitter has a frequency range that varies as a function of the output load. | 04-14-2011 |
| 20110096574 | Switching Power Controller and System - A switching power controller circuit comprises a first terminal pin for a high potential of a power supply for the controller circuit, a second terminal pin for providing output of switch drive signals and for receiving feedback signals, and a third terminal pin for receiving external current signals and for a low potential of the power supply. The switching power controller further comprises a clock generator, a pulse width modulation (PWM) generator, a reference generator, a power switch driver, a feedback signal sampler, a PWM comparator and a floating sampler. | 04-28-2011 |
| 20110110126 | CONTROLLER COMPENSATION FOR FREQUENCY JITTER - An example controller for use in a power supply in accordance with the present teachings includes a drive signal generator, a jitter signal generator and a compensator signal generator. The drive signal generator is coupled to output a drive signal having a switching period and a duty ratio to control switching of a switch that is to be coupled to the controller. The jitter signal generator is coupled to provide a jitter signal, where the switching period of the drive signal varies in response to the jitter signal. The compensator signal generator is coupled to provide a compensator signal responsive to the jitter signal, where the duty ratio of the drive signal is varied in response to the compensator signal. | 05-12-2011 |
| 20110122660 | CURRENT MODE DIGITAL CONTROL OF THE OUTPUT VOLTAGE OF A SWITCHING POWER SUPPLY - A method of controlling an output voltage of a pulse width modulation (PWM) converter with a PWM signal driving a power switch of the converter may include using a comparator to compare a reference voltage with a scaled output voltage of the converter, incrementing or decrementing an up/down counter at each pulse of a clock signal applied to the counter depending on a state of the comparator, and controlling the comparator to generate the PWM signal with a control voltage selected from a look-up table using a value of the counter. | 05-26-2011 |
| 20110176339 | Signal Transmission Arrangement - A signal transmission arrangement is disclosed. A voltage converter includes a signal transmission arrangement. | 07-21-2011 |
| 20110194317 | STACKED FLYBACK CONVERTER WITH INDEPENDENT CURRENT LOOP CONTROL - A voltage converter includes a transformer with a pair of primary coils and a secondary coil. The converter has a DC input and a capacitor bank, having a pair of capacitors, is connected across the DC input. A switch is associated with each primary coil. A gate drive feedback module outputs a pulse width modulated signal to drive either the first or second primary coil. A gate drive switch has as an input the pulse width modulated signal and outputs to the first second switch. A pulse steering logic module determines which of the first or second capacitors has a higher voltage and controls the gate drive switch to direct the pulse width modulated signal in response thereto. | 08-11-2011 |
| 20110228572 | OSCILLATOR HAVING TIME-VARIANT FREQUENCY DEVIATION AND RELATED POWER SUPPLY - An oscillator with time-variant frequency deviation for a power supply includes a signal generator for generating a first signal according to a clock signal and a comparing unit for adding an offset to at least one of the first signal and a threshold voltage corresponding to the first signal and for comparing the first signal and the threshold voltage after completion of the offset adding, to generate the clock signal whose frequency deviates with variation of the added offset. | 09-22-2011 |
| 20110242859 | ISOLATED PRIMARY CIRCUIT REGULATOR - An isolated primary circuit regulator is applied to a primary side of a transformer of a power supply. The isolated primary circuit regulator outputs a switching signal, and switches the transformer by using the switching signal, thereby stabilizing an output current. The isolated primary circuit regulator includes a discharge time detector, an oscillator, a pulse width modulator and a control circuit. The discharge time detector is used for detecting a discharge time of a switching current generated at a secondary side of the transformer. The oscillator is used for generating an oscillation signal. The control circuit is used for outputting an adjustment signal. The pulse width modulator outputs a switching signal according to the oscillation signal output by the oscillator and the adjustment signal output by the control circuit. The switching signal has a duty cycle and a frequency corresponding to the oscillation signal and the adjustment signal. | 10-06-2011 |
| 20110286248 | Adaptive Control for Transition Between Multiple Modulation Modes in a Switching Power Converter - In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap. | 11-24-2011 |
| 20110292694 | SYSTEM AND METHOD FOR PROVIDING CONTROL FOR SWITCH-MODE POWER SUPPLY - System and method for providing control for switch-mode power supply. According to an embodiment, the present invention provides a system for regulating a power converter. The system comprises a signal processing component that is configured to receive a first voltage and a second voltage, to process information associated with the first voltage and the second voltage, to determine a signal based on at least information associated with the first voltage and the second voltage, and to send the signal to a switch for a power converter. The switch is regulated based on at least information associated with the signal. The signal processing component is further configured to determine the signal to be associated a first mode, if the first voltage is higher than a first threshold. | 12-01-2011 |
| 20120002449 | Primary Side Voltage Control in Flyback Converter - In one embodiment, an apparatus includes a sampling component. The sampling component receives a first voltage signal on a primary side of a transformer and monitors the first voltage signal to determine a voltage sampling time. The determined voltage sampling time is when the first voltage signal is used to estimate a second voltage level on a secondary side of the transformer. The first component further samples the first voltage signal at the voltage sampling time to determine a first voltage level. A second component outputs a control signal to control a switch to regulate the second voltage level based on the first voltage level. | 01-05-2012 |
| 20120033459 | CIRCUIT REGULATOR AND SYNCHRONOUS TIMING PULSE GENERATION CIRCUIT THEREOF - A circuit regulator is used to generate a pulse-width-modulation signal, so as to control a power to be selectively input or not input to a primary side of a switching power supply. The circuit regulator includes a synchronous timing pulse generation circuit, outputs a starting pulse after performing signal process of time delay, timing pulse regulation, and synchronization control on a pulse-width-modulation signal and a discharging time signal of a secondary side, and accordingly effectively controls a pulse starting time of the pulse-width-modulation signal. Therefore, the synchronous timing pulse generation circuit can be applied to the circuit regulator, so as to further effectively prevent an inductor current of the switching power supply from entering a Continuous Conduction Mode (CCM). | 02-09-2012 |
| 20120033460 | High-Side Synchronous Rectifier Circuits and Control Circuits for Power Converters - A control circuit for a switching power converter is provided. The control circuit is installed between a secondary side and an output of the power converter and coupled to control a switching device. The control circuit includes a linear predict circuit, a reset circuit, a charge/discharge circuit, and a PWM circuit. The linear predict circuit is coupled to receive a linear predict signal from the secondary side for generating a charging signal. The reset circuit is couple to receive a resetting signal for generating a discharging signal. The charge/discharge circuit is coupled to receive the charging signal and the discharging signal for generating a ramp signal. The PWM circuit is coupled to receive the linear predict signal for enabling a switching signal and receive the ramp signal for resetting the switching signal. | 02-09-2012 |
| 20120075891 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE MODE AND CONSTANT CURRENT MODE IN FLYBACK POWER CONVERTERS WITH PRIMARY-SIDE SENSING AND REGULATION - System and method for regulating a power converter. The system includes a first signal generator configured to receive a first sensed signal and generate an output signal associated with demagnetization. The first sensed signal is related to a first winding coupled to a secondary winding for a power converter, and the secondary winding is associated with at least an output current for the power converter. Additionally, the system includes a ramping signal generator configured to receive the output signal and generate a ramping signal, and a first comparator configured to receive the ramping signal and a first threshold signal and generate a first comparison signal based on at least information associated with the ramping signal and the first threshold signal. Moreover, the system includes a second comparator configured to receive a second sensed signal and a second threshold signal and generate a second comparison signal. | 03-29-2012 |
| 20120106209 | METHOD FOR GENERATING A CURRENT LIMIT SIGNAL FOR A POWER CONVERTER WITHOUT SENSING AN INPUT VOLTAGE OF THE POWER CONVERTER - A method for generating a current limit signal for a power converter without sensing an input voltage of the power converter detects a current of a power switch of the power converter to obtain a current sense signal, counts a time for the current sense signal to increase from a first level to a second level, and according to the time, determines a current limit signal for limiting a maximum value of the current of the power switch for the power converter to have a constant maximum output power. | 05-03-2012 |
| 20120176822 | Synthetic ripple Hysteretic powder converter - A novel switching hysteretic power converter is presented. The converter includes the generation of a synthetic ripple signal and a feedback network to combine a signal in phase with the inductor current with a signal proportional to the regulated output voltage. The presented approach provides a switching boost converter with a much simpler control method with respect to conventional inductive boost power converters. The hysteretic control provides stable operation in all conditions with excellent load and line transient response. Furthermore the hysteretic control allows high frequency switching, reducing the size and cost of the passive components. The presented converter includes the Discontinuous Conduction Mode of operation to achieve very high efficiency at light loads. The presented approach can also be applied to buck switching power converters with excellent performance in terms of transient response, stability, efficiency and operation at high switching frequencies. The approach can be extended also to the hysteretic control of isolated switching flyback converters. | 07-12-2012 |
| 20120188802 | Switch Controller, Switch Control Method, Converter Using the Same, and Driving Method Thereof - Disclosed are a switch controller, a switch control method, a converter using the same, and a driving method thereof. A first voltage is generated by using a voltage that is input to an input terminal, and a soft start signal is generated by using the first voltage during a soft start duration. A switching operation is controlled by using the soft start signal during the soft start duration. | 07-26-2012 |
| 20120230065 | Two-Peak Current Control for Flyback Voltage Converters - A system including a switch configured to supply power to a load. A first comparator is configured to compare a first current through the switch to a first threshold. A second comparator is configured to compare the first current through the switch to a second threshold. The second threshold is greater than the first threshold. A current control module is configured to turn off the switch (i) for a first duration in response to the first current through the switch being greater than or equal to the first threshold and (ii) for a second duration in response to the first current through the switch being greater than or equal to the second threshold. The current control module is configured to adjust the second duration based on a difference between an estimated current through the load and a desired current through the load. | 09-13-2012 |
| 20120236605 | ULTRALOW NO-LOAD CONDUCTION LOSS DC POWER CONVERTER - An ultralow no-load conduction loss DC converter includes a DC power source, a transformer having a first winding, a first MOSET and a PWM controller at the primary side and a second winding, a third winding, a drive control unit, a rectifier unit and a second MOSFET at the secondary side. The second MOSFET, the drive control unit and the rectifier unit constitutes a combination circuit electrically coupled between one end of the second winding and one end of the third winding. The second MOSFET has set therein a body diode. The second winding and the second MOSFET forms a combination circuit electrically connected to a load. Thus, the decision to turn off the drive control unit is made at the secondary side so that non-load conduction loss can be minimized. | 09-20-2012 |
| 20120294048 | Start-Up Circuit for a Power Adapter - A start-up circuit for a power adapter and method of operating the same. In one embodiment, the power adapter includes a start-up circuit configured to provide an initial bias voltage for the power adapter. The power adapter also includes a crowbar circuit configured to turn on the start-up circuit upon loss of an ac mains voltage supplied to the power adapter. | 11-22-2012 |
| 20130003426 | SWITCHING POWER SUPPLY DEVICE - 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. | 01-03-2013 |
| 20130039098 | OFFLINE AC-DC CONTROLLER CIRCUIT AND A CONVERTER COMPRISING THE SAME - An offline AC-DC converter circuits including an overvoltage detection module, a current limiting module, a PWM module and a switch control module coupled to the above modules. The overvoltage detection module, the current limiting module and the PWM module share a common input terminal. The sampled current signal and the sampled voltage signal are provided at the common input terminal by way of time-division multiplexing. With the time-multiplexed terminal, overvoltage detection for the output voltage is performed during the period when the power transistor is cut off and a current through the power transistor is detected during the period when the power transistor conducts. The two signals are input by way of time-division multiplexing, which are not affected by each other. Accordingly, overvoltage in the output voltage can be precisely detected without additional terminals, and thus the overvoltage can be controlled. | 02-14-2013 |
| 20130343101 | FAST STARTUP CONTROL CIRCUIT FOR SWITCH MODE POWER SUPPLY - A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch. | 12-26-2013 |
| 20140016378 | FLYBACK-BASED POWER CONVERSION APPARATUS AND POWER CONVERSION METHOD THEREOF - A flyback-based power conversion apparatus and a power conversion method thereof are provided. By switching first and second detection switches disposed in a control chip and coupled to a multi-function pin of the control chip at different timings, the present invention applies a collocation of a voltage-current detection auxiliary circuit and a current detection circuit at a certain timing to execute a detection of the AC input voltage received by a flyback power conversion circuit, and the present invention applies a collocation of the auxiliary voltage-current detection circuit, an over temperature protection unit and an over voltage protection unit at another timing to execute detections of an over temperature protection and an over voltage protection. As the result, a single multi-function detection pin of the control pin is corresponding to a plurality of related function detections, so as to reduce the production cost of manufacturing the control chip. | 01-16-2014 |
| 20140029316 | METHOD AND CIRCUIT FOR CONTROLLING A SWITCHING REGULATOR - A method for controlling a switching regulator includes defining a waiting time during which a trigger signal corresponding to a recirculation signal of the switching regulator is ignored holding a control switch in an open condition, and detecting a number of local valleys of the recirculation signal during the waiting time. In particular, defining the waiting time is performed for each switching cycle by adding a first value, which is determined on the basis of a load on the regulator, to a second variable value, which is proportional to the number valleys detected during the waiting time of the preceding switching cycle. | 01-30-2014 |
| 20140063868 | POWER SUPPLY APPARATUS WITH POWER FACTOR CORRECTION AND PULSE WIDTH MODULATION MECHANISM AND METHOD THEREOF - A power supply apparatus that includes a pulse width modulation (PWM) based power conversion unit and a power factor correction (PFC) conversion unit is provided. The PWM-based power conversion unit is configured to receive a direct current (DC) input voltage and perform pulse width modulation on the received DC input voltage in response to a power supply request of a load, so as to generate a DC output voltage to the load. The PFC conversion unit is coupled to the PWM-based power conversion unit and configured to perform power factor correction on a rectification voltage associated with an alternating current (AC) input voltage, so as to generate the DC input voltage. The PFC conversion unit is further configured to adjust the generated DC input voltage in response to a variation of the load. | 03-06-2014 |
| 20140071718 | FLY-BACK POWER CONVERTING APPARATUS - A structure of a fly-back power converting apparatus is disclosed. The structure includes a power transistor, a current detector, a pulse width modulation (PWM) signal generator and a current limiter. The power transistor is coupled to an input voltage and receives a PWM signal. The current detector detects a current output from the power transistor and generates a detecting voltage according to the current. The PWM signal generator generates the PWM signal according to a comparing result by comparing the detecting voltage and a standard voltage. The current limiter generates the standard voltage according to a turn-on time of the power transistor. | 03-13-2014 |
| 20140146581 | Power Controller with Over Power Protection - A power controller with over power protection is disclosed, capable of providing a pulse-width-modulation signal to control a power switch. The power controller comprises a pulse width modulator, first and second oscillators, and an over power detector. The pulse width modulator generates the pulse-width-modulation signal. The first oscillator is coupled to the pulse width modulator, for determining a cycle time of the pulse-width-modulation signal. The second oscillator, independent from the first oscillator, determines a maximum over power duration. The over power detector detects the occurrence of an over power event. When the over power event lasts for the maximum over power duration, the pulse-width-modulation signal switches OFF the power switch constantly. | 05-29-2014 |
| 20140153297 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - An apparatus includes an ON/OFF controller for regulating an output of a switched mode power supply by selectively enabling current conduction by a power switch within enabled switching cycles and disabling current conduction by the power switch within disabled switching cycles. The controller includes a logic block and a time-to-frequency converter. The logic block generates a drive signal that enables the current conduction by the power switch within respective enabled switching cycles and disables the current conduction by the power switch within respective disabled switching cycles. The time-to-frequency converter generates a variable-frequency clock signal that defines durations of the switching cycles, where the time-to-frequency converter increases a duration of a switching cycle in response to a decrease in duration of current conduction by the power switch in a previously enabled switching cycle. | 06-05-2014 |
| 20140268925 | SWITCH CONTROL CIRCUIT, SWITCH CONTROL METHOD AND POWER SUPPLY DEVICE USING THE SAME - Embodiment relates to a switch control circuit, a switch control method, and a power supply using the switch control circuit. The power supply supplies power to a load using an input voltage. The switch control circuit controls a switching operation of the power switch that controls the power supply. The switch control circuit detects a duty of the power switch using a signal for controlling the switching operation of the power switch, detects the load using the feedback voltage, and determines a short-circuit of the sense resistor according to the detected duty and the detected load. | 09-18-2014 |
| 20140293661 | AC/DC CONVERTER WITH GALVANIC INSULATION AND SIGNAL CORRECTOR - An AC/DC converter comprising an input rectifier circuit connected in series with a primary winding ( | 10-02-2014 |
| 20150023071 | VOLTAGE CONVERTER CIRCUIT AND VOLTAGE CONVERTER CONTROLLER AND PARAMETER SETTING METHOD THEREFOR - A voltage converter circuit includes a voltage converter controller which generates a PWM signal to operate a power switch for voltage conversion. The voltage converter controller includes a sensing pin for sensing a current and the voltage converter controller receives a power supply. A parameter setting method for the voltage converter circuit includes: during a start-up stage, when the power supply increases above a predetermined reference level, the voltage converter controller outputting a current through the sensing pin; and setting at least one parameter of the voltage converter controller according to a voltage at the sensing pin. | 01-22-2015 |
| 20150029763 | CONTROLLER FOR GENERATING JITTERS IN A QUASI RESONANT MODE AND METHOD FOR GENERATING JITTERS IN A QUASI RESONANT MODE - A controller for generating jitters in a quasi resonant mode includes a feedback pin, a voltage generation unit, a pulse generator, and a comparator. The feedback pin is used for receiving a feedback voltage from a secondary side of a power converter. The voltage generation unit is used for generating a first voltage according to the feedback voltage and a pulse. The pulse generator is used for generating the pulse when a control signal controlling a power switch of a primary side of the power converter is enabled. The comparator is used for controlling enabling and disabling of a switching signal according to the first voltage and a variable reference voltage. The variable reference voltage is monotonously swung within a predetermined range according to a digital signal. | 01-29-2015 |
| 20150036394 | METHOD AND APPARATUS OF FREQUENCY MODULATION FOR POWER SAVING OF ADAPTIVE POWER CONVERTER - The present invention proposes a method for controlling an adaptive power converter. The method comprises: generating an output-sense signal by sampling a reflected voltage of a transformer; receiving a feedback signal related to an output power of the adaptive power converter; generating a clock signal in response to the feedback signal and the output-sense signal; generating a switching signal for switching the transformer and regulating an output voltage of the adaptive power converter. The reflected voltage is correlated to the output voltage of the adaptive power converter. The switching signal is generated in response to the feedback signal. The frequency of the switching signal is determined by the clock signal. The frequency of the switching signal is decreased in response to a decrement of the feedback signal. | 02-05-2015 |
| 20150055381 | MULTI-INPUT DIRECT CURRENT CONVERTER AND PFC CIRCUIT - The application discloses a multi-input DC converter and a PFC circuit. The multi-input DC converter of the application includes n diodes, a transformer, a switching transistor, a rectifier and filter circuit, and a load. The transformer includes a primary winding and a secondary winding, the number of turns of the primary winding is N | 02-26-2015 |
| 20150055382 | SYSTEM AND METHOD PROVIDING PROTECTION IN THE EVENT OF CURRENT SENSING FAILURE FOR POWER CONVERTER - System and method for protecting a power converter. The system includes a first comparator configured to receive a first threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a second comparator configured to receive a second threshold signal and the first signal and to generate a second comparison signal. The second threshold signal is different from the first threshold signal in magnitude. Moreover, the system includes a first detection component configured to receive at least the second comparison signal, detect the second comparison signal only if one or more predetermined conditions are satisfied, and generate a first detection signal based on at least information associated with the detected second comparison signal. | 02-26-2015 |
| 20150055383 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROLLER AND CONTROL METHOD THEREOF - The present invention relates to a constant voltage constant current (CVCC) controller, and associated control methods. In one embodiment, a CVCC controller for a flyback converter can include: (i) a current controller configured to generate an error signal by comparing an output current feedback signal against a reference current; (ii) a voltage controller configured to receive an output voltage feedback signal and a reference voltage, and to generate a control signal; (iii) a selector configured to control the flyback converter to operate in a first or a second operation mode based on the control signal, and to further generate a constant voltage or a constant current control signal based on the error signal; and (iv) a pulse-width modulation (PWM) controller configured to generate a PWM control signal to control a main switch, and to maintain the output voltage and/or current of the flyback converter as substantially constant. | 02-26-2015 |
| 20150062982 | Circuit Arrangement and Method for Actuating at Least One Switching Element of a Voltage Converter - The disclosure relates to a circuit arrangement for actuating at least one switching element of a voltage converter with a DC-isolating signal transformer that comprises a primary winding and at least one secondary winding, wherein an actuating signal for the switching element can be applied to the primary winding, and the secondary winding is connected to a switching input of the at least one switching element. The circuit arrangement is characterized by the fact that at least a part of the at least one secondary winding is connected in series with a switching path of the switching element in such a way that a switch current flowing through a switching path of the switching element flows through this part, and that a current measurement device is arranged in a series circuit with respect to the primary winding for determining the switch current. The disclosure furthermore relates to a method for actuating a switching element of a voltage converter, to a driver circuit for providing the actuating signal, which driver circuit can be used in connection with the circuit arrangement, and to the use of the circuit arrangement and/or of the method for providing an operating supply voltage to an inverter. | 03-05-2015 |
| 20150078041 | HARMONIC CONTROL METHOD AND CIRCUIT FOR FLYBACK SWITCHING POWER SUPPLY - In one embodiment, harmonic control method for a flyback switching power supply, can include: (i) generating a sense voltage signal based on an output signal of the flyback switching power supply; (ii) generating a first compensation signal by determining and compensating an error between the sense voltage signal and a reference voltage; (iii) generating a second compensation signal by regulating the first compensation signal based on a duty cycle of a main power switch in the flyback switching power supply; and (iv) generating a control signal based on the second compensation signal and a triangular wave signal, to control the main power switch such that the output signal is substantially constant and an input current follows a waveform variation of an input voltage of the flyback switching power supply. | 03-19-2015 |
| 20150109832 | POWER SUPPLY DEVICE - There is provided a power supply device having a primary side and a secondary side isolated from each other. The power supply device includes: a power supply unit converting power from the primary side to output the converted power to the secondary side; a control unit located on the secondary side and acquiring control information on the power supply unit based on a voltage output from the power supply unit; and a delivery unit delivering the control information to the primary side, the delivery unit including a Y-capacitor that provides an EMI noise path between the primary side and the secondary side. | 04-23-2015 |
| 20150295496 | FLYBACK-BASED POWER CONVERSION APPARATUS - A power conversion apparatus including a flyback power conversion circuit, a control chip and a detection auxiliary circuit is provided. The flyback power conversion circuit receives and converts an AC input voltage into a DC output voltage. The control chip generates a PWM signal in response to a power supply requirement to control operations of the flyback power conversion circuit, and the control chip has a multi-function detection pin. The detection auxiliary circuit assists the control chip to obtain an auxiliary voltage related to the DC output voltage via the multi-function detection pin, and thereby determines a transition time of the PWM signal according to the auxiliary voltage. Besides, the detection auxiliary circuit assists the control chip to execute detections of an over temperature protection (OTP) and an over voltage protection (OVP) via the multi-function detection pin respectively within first and second detection phases. | 10-15-2015 |
| 20150357924 | Dummy Load Controllers and Control Methods - Methods and apparatuses for providing a dummy load in a power converter are disclosed. The power converter has a primary winding and a secondary winding isolated from each other. The secondary winding can de-energize to provide an output voltage at an output node for powering a load. The winding voltage at across the secondary winding is sensed to provide a non-switching time, which is checked if it exceeds a predetermined reference time. The output voltage is compared with a predetermined safe voltage. A discharge current is provided as a dummy load to drain from the output node and to lower the output voltage if the on-switching time exceeds the predetermined reference time and the output voltage exceeds the predetermined safe voltage. | 12-10-2015 |
| 20160118898 | POWER SUPPLY APPARATUS WITH AUXILIARY WINDING SWITCHING CIRCUIT - A power supply apparatus includes a main converter, an auxiliary winding switching circuit and a pulse width modulation controller. The main converter includes a transformer. The transformer includes a primary side winding, a secondary side winding and an auxiliary winding. The auxiliary winding includes a first winding and a second winding. According to a secondary side voltage, the first winding induces to generate a first voltage, and the second winding induces to generate a second voltage. The first voltage is greater than the second voltage. The auxiliary winding switching circuit sends the first voltage to the pulse width modulation controller when the first voltage is not greater than a predetermined voltage. The auxiliary winding switching circuit sends the second voltage to the pulse width modulation controller when the first voltage is greater than the predetermined voltage. | 04-28-2016 |
| 20160134193 | POWER CONTROL APPARATUS WITH DYNAMIC ADJUSTMENT OF DRIVING CAPABILITY - A power control apparatus with dynamical adjustment of driving capability for converting an input power into an output power includes a transformer, a switch transistor connected to the transformer, a pulsed width modulation (PWM) driving controller generating a PWM signal and connected to the switch transistor, an isolation element, an output diode and an output capacitor. The first side coil of the transformer and the switch transistor are connected to the input power, the second side coil of the transformer is connected to the output diode and further connected to the output capacitor and an external load. The isolation element converts the output power into a feedback signal providing the PWM driving controller to dynamically control the PWM driving signal through adjustment so as to implement the optimal turn-on current for the switch transistor. Therefore, electrical performance and conversion efficiency are greatly improved by reducing the switching loss. | 05-12-2016 |
| 20160181929 | FLYBACK CONVERTER OUTPUT CURRENT EVALUATION CIRCUIT AND EVALUATION METHOD | 06-23-2016 |
| 20160181930 | CIRCUIT SUPPRESSING EXCESSIVE CURRENT IN STARTUP PHASE OF THE VOLTAGE CONVERTER AND METHOD THEREOF | 06-23-2016 |
