Entries |
Document | Title | Date |
20080304293 | Converter controller - A converter controller is disclosed. In one embodiment, a controller for a flyback converter includes a converter and a flyback controller. The converter is coupled to the flyback converter for receiving an auxiliary voltage and for generating a constant power voltage. The flyback controller is powered by the constant power voltage for controlling an output voltage of the flyback converter. Furthermore, the flyback converter comprises a transformer with a primary side and a secondary side. The output voltage and the auxiliary voltage are produced at the transformer. | 12-11-2008 |
20090027925 | SWITCHING POWER SUPPLY - A buck-boost converter of an H bridge type having a function for initially charging a smoothing output capacitor without a relay and a rush current preventing resistance. A compact and flat power supply is attained by employing a current critical mode H bridge system for a PFC converter and providing a function of initially charging a smoothing output capacitor to a converter circuit. | 01-29-2009 |
20090190379 | SWITCHING REGULATOR WITH BOOSTED AUXILIARY WINDING SUPPLY - A boosted auxiliary winding power supply for a switched-power converter circuit provides operating voltage for control and other circuits early in the start-up phase of converter operation. A boost circuit has an input coupled to the auxiliary winding to boost the voltage available from the auxiliary winding at least during start-up of the switched-power converter. The boost thereby provides a voltage that is greater than the voltage across the auxiliary winding during start-up of the switched-power converter. The boost circuit may be actively switched at a rate higher than a switching rate of the switched-power converter, to increase a rate of rise of the operating voltage. Polarity information, which may be provided from the switched-power converter control circuit, can be used to actively rectify the output of the auxiliary winding. | 07-30-2009 |
20090284994 | Control circuit and method for a flyback converter - A control circuit and method are provided for a flyback converter converting an input voltage to an output voltage, to compensate for an entry point of a burst mode of the flyback converter, so that the entry point is not affected by the input voltage, and audible noise resulted from a higher input voltage is reduced without impacting the light load efficiency of the flyback converter. | 11-19-2009 |
20090310388 | METHOD AND APPARATUS FOR MEASURING THE SWITCHING CURRENT OF POWER CONVERTER OPERATED AT CONTINUOUS CURRENT MODE - An apparatus for detecting a switching current of the power converter, wherein the apparatus includes a signal generation circuit, a sample-and-hold circuit, and a calculating circuit. The signal generation circuit generates a sample signal in accordance with the pulse width of a switching signal. The sample-and-hold circuit is coupled to receive the sample signal and switching current signal for generating a first current signal and a second current signal. The calculating circuit is coupled to receive the first current signal and the second current signal for generating output signals. The switching signal is used for switching the magnetic device of the power converter, and the switching current signal is correlated to the switching current of the power converter; the output signals are correlated to the value of the switching current of the power converter. | 12-17-2009 |
20100039836 | Novel Utilization of a Multifunctional Pin to Control a Switched-Mode Power Converter - An embodiment of the invention relates to a power converter including a resistor divider with an internal node to sense an input line voltage. The internal node is operable as a multifunctional pin. A controller compares a feedback voltage dependent on a power converter output characteristic to a current-sense signal including an offset dependent on a voltage of the internal node to control entry and exit of the power converter from burst mode operation. The node may be employed to manage power converter operation by sensing or controlling its voltage to signal operation in a standby or burst mode, to sense the input line voltage, to enable an external system to signal shutdown to the power converter, and to enable the power converter to signal a delayed restart condition to the external system. | 02-18-2010 |
20100188873 | COMPENSATING ON-TIME DELAY OF SWITCHING TRANSISTOR IN SWITCHING POWER CONVERTERS - A switch controller compensates the total on-time delay of the switch in a switching power converter. The intended on-time of the switching transistor for the present switching cycle is reduced by the time difference between the actual on-time and the intended on-time of the switching transistor in the previous switching cycle in the switching power converter. The total delay of the switch in the switching power converter, including propagation delay, switch turn-on delay, and switch turn-off delay, can be compensated in real time, cycle by cycle. | 07-29-2010 |
20100202165 | Dynamic Drive of Switching Transistor of Switching Power Converter - A switching power converter comprises a transformer ( | 08-12-2010 |
20100254167 | CONVERTER DEVICE AND CORRESPONDING METHOD - A converter circuit to produce a dc output signal from a stabilized input voltage may include a flyback inductor and a drive arrangement to drive said flyback inductor. A control unit is provided sensitive to the demagnetisation of said flyback inductor, said control unit configured to act on a first, a second and a third switch to effect in a cyclical manner the sequence including: a) producing a ramp-like increase of a magnetising current in said flyback inductor following activation of said first switch and said second switch; b) de-activating said first and second switch when the magnetising current in said flyback inductor reaches a predetermined peak value, c) activating said third switch thus producing energy transfer in said flyback inductor, and d) activating said first switch and de-activating said third switch when the voltage on said first electronic switch has reached zero. | 10-07-2010 |
20100265742 | SWITCHING REGULATOR WITH FREQUENCY LIMITATION AND METHOD THEREOF - The present invention provides a switching regulator with frequency limitation and method thereof. The switching frequency of the switching regulator is limited through setting of a minimum off time, so as to improve the efficiency and EMI distribution of the switching regulator. | 10-21-2010 |
20110063879 | SWITCHING POWER SUPPLY DEVICE AND SEMICONDUCTOR DEVICE - The switching power supply device includes: an input unit which receives an input voltage; a transformer which includes a primary winding and a secondary winding; an output unit which provides an output voltage; a switching element; and a control circuit. The control circuit includes: a T | 03-17-2011 |
20110085358 | METHOD AND APPARATUS FOR HIGH-SIDE INPUT WINDING REGULATION - A power supply control circuit for use in a power supply is disclosed. An example power supply control circuit includes a power switch coupled between first and second terminals. The first terminal is to be coupled to a positive input supply rail of the power supply. The second terminal is to be coupled to an energy transfer element input of the power supply. A sampling circuit is coupled to a third terminal. The sampling circuit coupled to sample a signal across the energy transfer element input of the power supply during an off time of the power switch to provide a sampled output of the power supply. The sampled output of the power supply is disabled from being be resampled by the sampling circuit during an on time of the power switch. A control circuit coupled to the sampling circuit and the power switch, the control circuit coupled to switch the power switch in response to the sampled output of the power supply. | 04-14-2011 |
20110103102 | VOLTAGE CONVERTER WITH HIGH EFFICIENCY - A voltage converter transmits energy in multiple stages using a charge pump so as to decrease the voltage rating of the secondary side of the transformer and reduce the size of the transformer. Meanwhile, the voltage converter stores and recycles the leakage inductance energy by using a snubber circuit so as to increase the efficiency. | 05-05-2011 |
20110110122 | FLYBACK CONVERTER SYSTEM CAPABLE OF PREVENTING TWO SIDE SWITCHES FROM BEING TURNED ON SIMUTANEOUSLY - A flyback converter system prevents a primary side switch and a secondary side switch from being turned on simultaneously through a controller. The controller includes a turning on switch module, a turning off switch module, and an enabling switch module. The turning on switch module is for turning on the secondary side switch. The turning off switch module switches off the secondary side switch according to the impedance of a load and the switch cycle of the secondary side switch. The enabling switch module enables the secondary side switch according to the impedance of the load. | 05-12-2011 |
20110116287 | SWITCHING CONTROLLER HAVING SWITCHING FREQUENCY HOPPING FOR POWER CONVERTER - A switching controller having switching frequency hopping for a power converter includes an oscillator generating a pulse signal for determining a switching frequency of a switching signal, a maximum duty-cycle circuit generating a maximum duty-cycle signal in response to the switching signal for determining the switching frequency of the switching signal, a pattern generator generating a digital pattern code in response to a clock signal, a programmable capacitor coupled to the pattern generator and the oscillator for modulating the switching frequency of the switching signal in response to the digital pattern code, and a PWM circuit coupled to the oscillator and the maximum duty-cycle circuit for generating the switching signal in accordance with the pulse signal and the maximum duty-cycle signal. A maximum on-time of the switching signal is limited by the maximum duty-cycle signal. The switching signal is utilized to switch a transformer of the power converter. | 05-19-2011 |
20110182089 | Controller for a Power Converter and Method of Operating the Same - A controller for a power converter and method of operating the same. In one embodiment, the controller includes a primary peak current circuit configured to produce a reference voltage corresponding to a primary peak current through a primary winding of a transformer of a power converter, and an offset corrector configured to provide an offset voltage to compensate for delays in the power converter. The controller also includes a summer configured to provide an offset reference voltage as a function of the reference voltage and the offset voltage, and a comparator configured to produce a signal to turn off a power switch coupled to the primary winding of the transformer as a function of the offset reference voltage. | 07-28-2011 |
20110199793 | SWITCHING MODE POWER SUPPLY WITH PRIMARY SIDE CONTROL - The present technology are directed to switching mode power supplies with primary side control. In one embodiment, the switching mode power supply provides an equivalent current signal which represents a load current. The equivalent current signal is then used to control a switching circuit in the switching mode power supply. | 08-18-2011 |
20110199794 | METHOD FOR CONTROLLING A SWITCHING REGULATOR AND RELATED SWITCHING REGULATOR - An embodiment of a power-supply controller comprises a switching-control circuit, an error amplifier, and a signal generator. The switching-control circuit is operable to control a switch coupled to a primary winding of a transformer, and the error amplifier has a first input node operable to receive a feedback signal, a second input node operable to receive a comparison signal, and an output node operable to provide a control signal to the switching-control circuit. The signal generator is operable to generate either the feedback signal or the comparison signal in response to a compensation signal that is isolated from a secondary winding of the transformer and that is proportional to a load current through a conductor disposed between the secondary winding and a load. | 08-18-2011 |
20110216559 | Constant-Current Control Module using Inverter Filter Multiplier for Off-line Current-Mode Primary-Side Sense Isolated Flyback Converter - A fly-back AC-DC power converter has a constant-current control loop that senses the primary output current in a transformer to control the secondary output without an expensive opto-isolator. A primary-side control circuit can use either a Quasi-Resonant (QR) or a Pulse-Width-Modulation (PWM) control loop to switch primary current through the transformer on and off. A feedback voltage is compared to a primary-side voltage sensed from the primary current loop to turn the switch on and off. A multiplier loop generates the feedback voltage using a multiplier. A level-shift inverter and a low-pass filter act as the multiplier by multiplying an off duty cycle of the switch by the feedback voltage to generate a filtered voltage. A high-gain error amp compares the filtered voltage to a reference voltage to generate the feedback voltage. The multiplier produces a simple relationship between the secondary current and the reference voltage, yielding simplified current control. | 09-08-2011 |
20110228570 | SWITCHING MODE POWER SUPPLIES WITH PRIMARY SIDE CONTROL AND ASSOCIATED METHODS OF CONTROL - Switching mode power supplies with primary side control and associated methods of control are disclosed. In one embodiment, a signal with input voltage information and a signal with both input voltage information and output voltage information are provided to a subtracter to generate a feedback signal that is indicative of the output voltage. The feedback signal is then used to control the switching mode power supply. | 09-22-2011 |
20110242858 | SWITCHING CONVERTER SYSTEMS WITH ISOLATING DIGITAL FEEDBACK LOOPS - Switching converter systems are provided to control output voltage across a load by means of a converter forward path and a converter feedback path. The forward path preferably includes a transistor, an inductive element, a diode and a capacitor arranged to switchably exchange energy with the capacitor to thereby generate the output voltage. The feedback path preferably extends from the capacitor and is configured to digitally control a duty cycle of the transistor in response to the output voltage. In a system embodiment, the feedback path includes at least one comparator arranged to provide a digital error signal in response to a comparison of the output voltage to a reference voltage; a first isolation channel configured to isolatably transport a clock signal to digitally gate the error signal; a second isolation channel configured to isolatably transport the error signal; and a controller coupled to the first and second isolation channels and configured to control the duty cycle in response to the error signal. A transformer is preferably inserted into the first and second isolation channels to enhance isolation and, preferably, the first and second isolation channels respectively include first and second digital gates that each have an output port coupled to an input port of the other. | 10-06-2011 |
20110261596 | CONTROL CIRCUIT FOR PRIMARY SIDE CONTROL OF SWITCHING POWER SUPPLY - A switched mode power supply (SMPS) includes a transformer with a primary winding, a secondary winding, an auxiliary winding, and a power switch coupled to the primary winding. During one switching cycle, the auxiliary winding provides a feedback signal which includes a first voltage pulse that is induced after the power switch is turned on and a second voltage pulse that is induced after the power switch is turned off. A control circuit includes a circuit for generating a sampling signal for sampling the second voltage pulse in a switching cycle at a time that is determined based on the first voltage pulse in the same switching cycle. A sample-and-hold circuit is configured for sampling and storing the second voltage pulse in response to the sampling signal. A switching signal generating circuit is configured to generate a switching signal for controlling the power switch based on an output of the sample-and-hold circuit. | 10-27-2011 |
20110299305 | DIGITAL DYNAMIC DELAY MODULATOR AND THE METHOD THEREOF FOR FLYBACK CONVERTER - A digital dynamic delay modulator and the method thereof are applied to a flyback converter. A first input voltage signal from the flyback converter is received and compared with a threshold voltage to determine whether a counting condition is matched. When the counting condition is matched, an integer predetermined count number is counted to determine a delay time. After finishing the counting, a first output signal is generated to turn on a switching device for the flyback converter. The slope of the first input voltage signal is detected when the switching device is turned on, and the slope is used to adjust the count number with integer increment/decrement. Therefore, the delay time for switching the flyback converter can be precisely controlled in digital and dynamic manner. | 12-08-2011 |
20110317454 | DUAL SWITCHES FLYBACK POWER CONVERTER WITH WIDE INPUT VOLTAGE RANGE - A dual switches Flyback power converter with a wide input voltage range according to the present invention comprises an input diode and an energy-store capacitor. The input diode can prevent the reflected voltage from the power transformer of the power converter to charge the electrolytic capacitor of the power converter. The energy-store capacitor will store the reflected voltage and the energy of the leakage inductor of the power transformer. The energy stored in the energy-store capacitor will be recycled to the output voltage of the power converter. Further, the input diode can be replaced by an input transistor to prevent the reflected voltage from the power transformer to charge the electrolytic capacitor. | 12-29-2011 |
20120002448 | METHOD AND APPARATUS FOR ON/OFF CONTROL OF A POWER CONVERTER - A power converter is disclosed. An example power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element and the power converter input. A feedback sampling circuit is coupled to receive a feedback signal representative of the power converter output to generate feedback signal samples during switching cycles. A switch conduction scheduling circuit is coupled to determine enabling and disabling of the power switch in future switching cycles in response to the feedback signal samples from a present switching cycle and one or more past switching cycles. A switch conduction control circuit is coupled to enable or disable conduction of the power switch during a switching cycle to control an amount of energy transferred from the power converter input to the power converter output. | 01-05-2012 |
20120026758 | APPARATUS AND METHOD FOR CONTROLLING SWITCH OF FLYBACK CONVERTER FOR SOLAR GENERATING SYSTEM - There is provided an apparatus and method for controlling a switch of a flyback converter for a solar generating system. The apparatus for controlling a switch of a flyback converter for a solar generating system includes: an MPPT controller generating a current command value for a maximum power point tracker of a solar cell module, based on input voltage, input current, and output voltage of the flyback converter; a current controller generating a current control signal for tracking the current command value; an output current command value generator generating the phase and magnitude command value of the output current, based on the phase of the output voltage and the current control signal; and a switch controller controlling the main switch of the flyback converter, based on the phase and magnitude command value of the output current, thereby simplifying a circuit while solving disadvantages of a discontinuous conduction mode and a boundary conduction mode. | 02-02-2012 |
20120039098 | Controller for a Power Converter and Method of Operating the Same - A controller for a power converter and method of operating the same. In one embodiment, the controller includes a peak detector, coupled to a circuit element of the power converter, configured to produce a signal corresponding to a peak current through a circuit element. The controller also includes an adjustable reference circuit responsive to a difference between the signal and a reference signal corresponding to a desired peak current to produce a corrected signal corresponding to the peak current. | 02-16-2012 |
20120044723 | SYSTEMS AND METHODS FOR REDUCING STANDBY POWER CONSUMPTION OF SWITCH-MODE POWER CONVERTERS - Power conversion system and method. The system includes a first capacitor including a first capacitor terminal and a second capacitor terminal, a second capacitor including a third capacitor terminal and a fourth capacitor terminal, and a plurality of diodes including a first diode, a second diode, a third diode, and a fourth diode. The first diode is coupled to the second diode at a first node, the second diode is coupled to the fourth diode at a second node, the fourth diode is coupled to the third diode at a third node, and the third diode is coupled to the first diode at a fourth node. Additionally, the system includes a fifth diode including a first anode and a first cathode and a sixth diode including a second anode and a second cathode. | 02-23-2012 |
20120081930 | METHOD AND APPARATUS TO LIMIT MAXIMUM SWITCH CURRENT IN A SWITCHING POWER SUPPLY - An integrated circuit for use in a power supply includes a drive signal generator, a short on time detector, and an oscillator. The drive signal generator generates a drive signal in response to a clock signal. The short on time detector provides an output indicating that consecutive on times of the drive signal are short on times. An on time of the drive signal is a short on time if a switch current of the switch exceeds a current limit after a leading edge blanking period and if the on time of the switch is less than or equal to a sum of the leading edge blanking period and a current limit delay time period. The oscillator generates the clock signal and changes a frequency of the clock signal from a first frequency to a lower second frequency in response to the output of the short on time detector. | 04-05-2012 |
20120106208 | SEMICONDUCTOR CONTROL DEVICE FOR A SWITCHING REGULATOR AND A SWITCHING REGULATOR USING THE SEMICONDUCTOR CONTROL DEVICE - A semiconductor control device can include a current detection signal input terminal, a feedback signal input terminal, a driving signal output terminal and a voltage adjusting circuit that delivers a voltage similar to a voltage of a primary winding of the flyback transformer to the current detection signal input terminal. The device can also include an oscillator circuit connected to the feedback signal input terminal; a one-shot circuit connected to the oscillator circuit, an RS flip-flop circuit that generates a driving signal to be delivered to the driving signal output terminal. A bottom detection section can receive a one-shot signal from the one-shot circuit, the current detection signal, and an output signal from the RS flip-flop circuit, and detect a bottom of the current detection signal to set the RS flip-flop circuit based on the detected bottom detection signal. | 05-03-2012 |
20120170330 | SINGLE-STAGE PFC CONVERTER WITH CONSTANT VOLTAGE AND CONSTANT CURRENT - An exemplary embodiment of a power converter is provided. The power converter includes a transformer, a power device, a switching controller, and a capacitor. The power device is coupled to the transformer for switching the transformer to product output of the power converter. The switching controller receives a feedback signal for generating a switching signal coupled to drive the power device. An input circuit of the switching controller is coupled to the transformer to sample an input signal for generating the feedback signal, and the input signal is correlated to the output of the power converter. The capacitor is coupled to the switching controller to provide frequency compensation for a feedback loop of the power converter. Input of the power converter is without an electrolytic capacitor, and a maximum output current of the power converter is a constant current. | 07-05-2012 |
20120188801 | FLYBACK POWER SUPPLY SYSTEM - A flyback power system includes a rectifier and filter circuit, a pulse width modulation (PWM) controller, a feedback circuit, a master converter circuit, a slave converter circuit, and a slave converter control circuit. The master converter circuit continuously converts power signals from the rectifier and filter circuit into first direct current (DC) power signals to drive load according to PWM signals of the PWM controller when the flyback power system powered on. The slave converter circuit converts the power signals from the rectifier and filter circuit into second DC power signals according to the PWM signals, and superposes the second DC power signals to the first DC power signals to drive the load when the load is heavy. The slave converter control circuit detects whether the load is heavy, and controls the PWM signals whether to input into the slave converter circuit according to a state of the load. | 07-26-2012 |
20120206944 | CONTROL CIRCUIT FOR BURST SWITCHING OF POWER CONVERTER AND METHOD THEREOF - This invention provides a control circuit for burst switching of a power converter comprising: an adaptive circuit generating an adaptive threshold in response to a feedback signal correlated to an output load of the power converter; and a switching circuit generating a switching signal to switch a transformer of the power converter in accordance with the adaptive threshold and the feedback signal for regulating an output of the power converter. | 08-16-2012 |
20120224399 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - An example controller for use in a power supply regulator includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output. | 09-06-2012 |
20120236604 | FLYBACK CONVERTER WITH LEADING EDGE BLANKING MECHANISM - A flyback converter having a leading edge blanking (LEB) element keeps detecting whether or not primary-side current of the flyback converter reaches a predetermined threshold, beyond which the flyback converter could be damaged, in a predetermined LEB time corresponding to a leading edge of primary-side current. The flyback converter is turned off when the primary-side current exceeds the predetermined threshold. | 09-20-2012 |
20120300506 | POWER SUPPLY DEVICE AND DRIVING METHOD THEREOF - The present invention relates to a power supply device generating an output power by using an AC line voltage generated through rectification of an AC input, and a driving method thereof. The power supply device controls the switching operation of the power switch by using a sensing voltage corresponding to the drain current flowing to the power switch and the feedback voltage corresponding to the output voltage. The power supply device controls the feedback current every switching cycle to generate a threshold voltage, and compares the sensing voltage and the threshold voltage to control the turn-off of the power switch. The feedback current includes the first current to generate the feedback voltage, and the threshold voltage follows a curved line waveform in which the increasing slope is decreased during the switching cycle. | 11-29-2012 |
20130033905 | SYSTEMS AND METHODS FOR FLYBACK POWER CONVERTERS WITH SWITCHING FREQUENCY AND PEAK CURRENT ADJUSTMENTS BASED ON CHANGES IN FEEDBACK SIGNALS - System and method for regulating a power converter. The system includes a first comparator configured to receive a first input signal and a second input signal and generate a first comparison signal based on at least information associated with the first input signal and the second input signal, a pulse-width-modulation generator configured to receive at least the first comparison signal and generate a modulation signal based on at least information associated with the first comparison signal, a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter, and a voltage-change-rate detection component configured to sample the feedback signal to generate a first sampled signal for a first modulation period and to sample the feedback signal to generate a second sampled signal for a second modulation period. | 02-07-2013 |
20130051086 | CONTROL CIRCUITS AND CONTROL METHODS FOR OVER VOLTAGE PROTECTION IN POWER SUPPLIERS - Disclosed include a control circuit adapted for a power controller powered by an operation voltage. When the operation voltage exceeds an over-voltage reference, the power controller stops power conversion provided by a power converter. The control circuit comprises a slope detector detecting a variation slope of the operation voltage. When the variation slope exceeds a drop rate, the slope detector recovers the power conversion. When the power conversion is recovered the power controller compares the operation voltage with the over-voltage reference. | 02-28-2013 |
20130058138 | METHOD AND APPARATUS TO LIMIT MAXIMUM SWITCH CURRENT IN A SWITCHING POWER SUPPLY - An integrated circuit for use in a power supply includes a drive signal generator, a first delay, a second delay, a comparator, a first logic, a first short on time detector, and a second logic. The drive signal generator generates a drive signal to control a switch in response to a clock signal. The short on time detector sets the first latch indicating that an on time of the switch is a short on time. The second logic is coupled to detect long pulses of the drive signal to reset the first latch indicating that the on time of the switch is not a short on time. An on time of the drive signal is a short on time if a switch current of the switch exceeds a current limit after a sum of a leading edge blanking period and a current limit delay time period. | 03-07-2013 |
20130208513 | Circuit for a Switched Mode Power Supply - A circuit for a switched mode power supply having a winding. The circuit comprising: an input configured to receive a winding voltage derived from the winding; a differentiation element configured to differentiate the winding voltage with respect to time in order to determine a derivative signal and compare the derivative signal with a threshold value; a steady state detector configured to set a zero derivative signal when the derivative signal has not exceeded the threshold value for a predetermined period of time, and a logic arrangement configured to identify an end of a demagnetization stroke of the switched mode power supply when the derivative signal crosses a final threshold value after the zero derivative signal has been set. | 08-15-2013 |
20130301311 | SWITCHING MODE POWER SUPPLY AND THE METHOD THEREOF - A switching mode power supply, having: an input port; an output port; an energy storage component and a pair of power switches coupled between input port and the output port; an error amplifier configured to generate an amplified error signal based on the feedback signal and the reference signal; an error comparator configured to generate a frequency control signal based on the amplified error signal and the first sawtooth signal; a peak current generator configured to generate a peak current signal based on the frequency control signal; a peak current comparator configured to generate a current limit signal based on the peak current signal and the current sense signal; and a logic circuit configured to generate a switching signal to control the power switches based on the frequency control signal and the current limit signal. | 11-14-2013 |
20130322130 | METHOD OF FORMING A POWER SUPPLY CONTROLLER AND STRUCTURE THEREFOR - In one embodiment, a power supply controller is configured to adjust a peak value of a primary current through a power switch responsively to a difference between a demagnetization time and a discharge time of the parasitic leakage inductance of a transformer. | 12-05-2013 |
20130336020 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - An example power supply regulator includes an energy transfer element, a switch, and a controller. The controller includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output. | 12-19-2013 |
20130336021 | VARIABLE FREQUENCY TIMING CIRCUIT FOR A POWER SUPPLY CONTROL CIRCUIT - A timing circuit of a controller generates a clock signal having a switching period for use by a pulse width modulation (PWM) circuit to control a switch of a power supply. The switching period of the clock signal is based on a charging time plus a discharging time of a capacitor included in the timing circuit. A first current source charges the capacitor while the timing circuit is in a normal charging mode. A second current source charges the capacitor while the timing circuit is in an alternative charging mode that is when the on time of the switch exceeds a threshold time. The current provided by the second current source is less than the current provided by the first current source such that the switching period of the clock signal is increased in response to the timing circuit entering the alternative charging mode. | 12-19-2013 |
20140009974 | Control Methods and Apparatuses for Switching Mode Power Supplies - Embodiments disclose control methods and control apparatuses for a switched mode power supply. The switched mode power supply comprises a current-controllable device. A driving current is provided to turn ON the current-controllable device. A conduction current passing through the current-controllable device is detected. The driving current is controlled according to the conduction current. The higher the conduction current the higher the driving current. | 01-09-2014 |
20140009975 | POWER CONVERTER WITH DEMAND PULSE ISOLATION - The present invention provides a switched-mode power converter with regulation demand pulses sent across a galvanic isolation barrier. | 01-09-2014 |
20140022825 | METHOD AND APPARATUS TO SELECT A PARAMETER/MODE BASED ON A MEASUREMENT DURING AN INITIALIZATION PERIOD - A power supply control circuit includes a threshold detection circuit coupled to a first terminal to measure a signal at the first terminal during a duration of an initialization period after a fourth terminal has been charged to a supply threshold value. A regulator circuit is coupled between a second terminal and the fourth terminal to charge the fourth terminal to the supply threshold value during the initialization period of the power supply control circuit. A selection circuit is coupled to the threshold detection circuit to select a parameter/mode in response to the signal measured at the first terminal. The first terminal is further coupled to receive one or more additional signals during normal operation at times other than the initialization period to provide at least one additional function for the power supply control circuit after the initialization period is complete. | 01-23-2014 |
20140029315 | SYSTEMS AND METHODS FOR CURRENT CONTROL OF POWER CONVERSION SYSTEMS - System and method for regulating an output current of a power conversion system. An example system controller for regulating an output current of a power conversion system includes a driving component, a demagnetization detector, a current-regulation component, and a signal processing component. The driving component is configured to output a drive signal to a switch in order to affect a primary current flowing through a primary winding of the power conversion system. The demagnetization detector is configured to receive a feedback signal associated with an output voltage of the power conversion system and generate a detection signal based on at least information associated with the feedback signal. The current-regulation component is configured to receive the drive signal, the detection signal and a current-sensing signal and output a current-regulation signal based on at least information associated with the drive signal, the detection signal, and the current sensing signal. | 01-30-2014 |
20140036551 | METHOD AND APPARATUS FOR ON/OFF CONTROL OF A POWER CONVERTER - A power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element and the power converter input. A feedback sampling circuit is coupled to receive a feedback signal representative of the power converter output to generate at least one feedback signal sample during each switching cycle. A switch conduction scheduling circuit is coupled to set a number of enabled cycles and a number of disabled cycles of the power switch in a plurality of future switching cycles in response to the feedback signal samples for each present switching cycle and one or more past switching cycles. A switch conduction control circuit is coupled to enable or disable conduction of the power switch during a switching cycle to control an amount of energy transferred from the power converter input to the power converter output. | 02-06-2014 |
20140063865 | DC/DC CONVERTER - A pulse modulator generates a pulse modulation signal S | 03-06-2014 |
20140092645 | CONTROL CIRCUIT AND TERMINAL FOR CABLE COMPENSATION AND WAKE-UP OF PRIMARY-SIDE REGULATED POWER CONVERTER - A control circuit of a power converter is provided. It comprises a signal generation circuit generating an oscillation signal in accordance with an output load. A PWM circuit generates a switching signal according to a voltage-loop signal, a current-loop signal and the oscillation signal for regulating an output of the power converter. A regulation circuit receives a compensation signal for an output cable compensation and a wake-up. The compensation signal is coupled to increase a switching frequency of the switching signal once the output of the power converter is lower than a low-voltage threshold. The control circuit reduces the voltage drop of the output when the output load is changed. | 04-03-2014 |
20140104894 | SWITCHING POWER SUPPLY SYSTEM - A control circuit controlling the driving of a switching device includes an under voltage limiting operation circuit stopping the operation of the control circuit when a power supply voltage supplied from the auxiliary winding of an insulating transformer becomes lower than a predetermined power supply lower limit voltage, an FB voltage decision circuit stopping the driving of the switching device when a feedback voltage indicating the state of a load becomes lower than the predetermined threshold value, a flip-flop brought into a set state by an output of the FB voltage decision circuit and a reset state when the power supply voltage exceeds the voltage ensuring the normal operation of the control circuit, and a switching circuit to set the power supply lower limit voltage in the under voltage limiting operation circuit, lower than that of the normal operation when the flip-flop is set. | 04-17-2014 |
20140104895 | METHOD AND APPARATUS FOR PROGRAMMING A POWER CONVERTER CONTROLLER WITH AN EXTERNAL PROGRAMMING TERMINAL HAVING MULTIPLE FUNCTIONS - A power converter includes an energy transfer element and a power switch coupled the energy transfer element and an input of the power converter. A control circuit is coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of an output of the power converter. A programming interface circuit is coupled to the control circuit and a coupling switcher coupled to the programming interface circuit. A programming terminal is selectively coupled to the programming interface circuit through the coupling switcher. A programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, and is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter. | 04-17-2014 |
20140119065 | SWITCHING POWER-SUPPLY DEVICE - A switching power-supply device comprises: a transformer; a switching element connected in series with a primary coil; an output voltage generation circuit to generate an output voltage from a voltage generated in a secondary coil; a control circuit power-supply-voltage generation circuit to generate a power-supply voltage from a voltage generated in an auxiliary coil; a feedback control circuit to control an ON width of the switching element by using the voltage generated in the auxiliary coil; a voltage reduction detection circuit to output a pulse signal to the secondary coil when a reduction of the output voltage is detected; a voltage-reduction-signal detection circuit to detect the voltage reduction signal transmitted to the primary coil from the secondary coil; and a trigger circuit to output a trigger signal to turn on the switching element when the voltage reduction signal is detected by the voltage-reduction-signal detection circuit. | 05-01-2014 |
20140126246 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - An on/off controller device includes a control circuit to generate a control signal to switch a power switch between an on state and an off state to transfer energy from a primary side to a secondary side of a switched mode power supply. A comparator is coupled to generate an enable signal that enables and disables the switching of the power switch by the control circuit. The comparator compares a feedback signal with a variable threshold and switches the enable signal between enabling and disabling the switching of the power switch. The variable threshold is modulated to increase a fundamental frequency of the switching of the power switch by the control circuit. The variable threshold is modulated with a fixed amplitude pulse that is combined with a second threshold to modulate the variable threshold between a first higher value and a second lower value. | 05-08-2014 |
20140146578 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE CONTROL AND CONSTANT CURRENT CONTROL - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal, a second controller terminal and a third controller terminal. The system controller is configured to receive an input signal at the first controller terminal and turn on or off a switch based on at least information associated with the input signal to adjust a primary current flowing through a primary winding of the power conversion system, receive a first signal at the second controller terminal from the switch, and charge a capacitor through the third controller terminal in response to the first signal. | 05-29-2014 |
20140177289 | CONTROL CIRCUIT FOR REDUCING CURRENT ERROR OF OUTPUT OF POWER CONVERTER AND CONTROL METHOD THEREOF - A control circuit adjusts the output of a power converter by controlling a power switch, in which a primary side of a transformer, the power switch and a sensing resistor are connected in series to ground. The control circuit includes a peak current emulating unit, an error amplifier, a comparator, and a control signal generator. The peak current emulating unit samples sampling voltages from the sensing resistor and obtains a real current sensing voltage and an current sensing voltage using the sampling voltages. The error amplifier receives a fixed reference voltage and a DC voltage generated from the output of the power converter, and generates an error signal. The comparator receives the real current sensing voltage and the error signal and generates a transition signal. The control signal generator receives the transition signal and generates a control signal for controlling the power switch. | 06-26-2014 |
20140177290 | SWITCH MODE POWER SUPPLY, CONTROL CIRCUIT AND ASSOCIATED CONTROL METHOD - A switch mode power supply having an output terminal configured to provide an output voltage, the switch mode power supply has a first switch and a control circuit. The control circuit is configured to provide a switching control signal to control the first switch. The control circuit is configured to provide the switching control signal based on a first pulse signal having a first frequency and a second frequency for a light load condition, and the control circuit is configured to provide the switching control signal based on a second pulse signal for a non-light load condition. | 06-26-2014 |
20140192563 | DUAL-MODE SWITCHING POWER CONTROL DEVICE - A dual-mode switching power control device includes an electric transformer, a PWM driving controller, a switching transistor, an isolation element, an output diode and an output capacitor. The PWM driving controller is connected to the switching transistor coupled to the electric transformer. The first side inductor of the electric transformer and the switching transistor are coupled to an input power, and the second side inductor of the electric transformer is coupled to the output diode. The output capacitor and a load are connected in series. The output power is converted into a feedback signal by the isolation element. The PWM driving controller determines to perform DCM or CCM based on the feedback signal to control the current flowing through the electric transformer, and the output power is generated. Therefore, the efficiency of power conversion is improved and is suitable for high power applications. | 07-10-2014 |
20140204625 | SECONDARY CONTROLLER FOR USE IN SYNCHRONOUS FLYBACK CONVERTER - A secondary controller for use in a synchronous flyback converter includes a comparator, a drive circuit, and logic circuitry. The comparator is coupled to generate a compare signal in response to a comparison of a threshold to an input signal representative of a secondary winding voltage of the synchronous flyback converter. The drive circuit is coupled to generate a drive signal to control a first switch to be coupled to a primary side of the synchronous flyback converter. The drive signal is coupled to be generated by the drive circuit in response to a feedback signal representative of an output of the synchronous flyback converter. The logic circuitry is coupled to the drive circuit and coupled to the comparator. The logic circuitry is also coupled to generate a control signal to control a second switch in response to the drive signal and in response to the compare signal. | 07-24-2014 |
20140211516 | METHOD AND APPARATUS FOR INPUT CHARGE CONTROL OF A POWER SUPPLY - An example method of controlling a power supply to have a constant current output includes receiving an input current sense signal, an input voltage sense signal, and an output voltage sense signal. A control signal is then generated to control switching of a switch of the power supply to regulate an output current of the power supply. The generating of the control signal includes integrating the input current sense signal during a switching period of the control signal to generate an integrated signal representative of a charge taken from an input voltage source of the power supply. Generating the control signal also includes controlling the switching of the switch such that the integrated signal is proportional to a ratio of the output voltage sense signal to the input voltage sense signal. | 07-31-2014 |
20140233271 | SYSTEMS AND METHODS FOR REDUCING ELECTROMAGNETIC INTERFERENCE BY ADJUSTING SWITCHING PROCESSES - System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a signal generator and a driving component. The signal generator is configured to receive a feedback signal associated with an output signal of a power conversion system and a current sensing signal associated with a primary current flowing through a primary winding of the power conversion system and generate a modulation signal based on at least information associated with the feedback signal and the current sensing signal. The driving component is configured to receive the modulation signal and output a drive signal to a switch based on at least information associated with the modulation signal. | 08-21-2014 |
20140268913 | Adaptive Peak Power Control - A switching power converter includes a controller configured to transition from a first operating mode to a second operating mode by determining the operating conditions at the transition point between the operation modes. The controller uses the value of the voltage-time product determined at the boundary between the first and second operating modes to predict the voltage to be applied to the primary-side of the transformer. Using the predicted voltage, the controller can adjust the peak-power control threshold on a cycle-by-cycle basis without the transformer reaching saturation. | 09-18-2014 |
20140268914 | METHOD OF CONTROLLING SYNCHRONOUS RECTIFIER FOR POWER CONVERTER, CONTROL CIRCUIT, AND POWER CONVERTER THEREOF - A method for controlling a synchronous rectifier for a power converter, a control circuit, and a power converter thereof are provided. The method comprises the following steps: turning on a transistor by a rectifier; generating a switching-period signal in accordance with a period of a voltage-sensing signal; generating a turn-on-period signal in accordance with a turned-on period of the rectifier; generating a first disabling signal responding to the switching-period signal; and generating a second disabling signal in response to the turn-on-period signal. The transistor is turned off in response to the first disabling signal and the second disabling signal, and the voltage-sensing signal is related to the switching waveform of a transformer. | 09-18-2014 |
20140301115 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES - A controller for use in a power converter includes an oscillator that generates a first signal that determines a duration of a switching cycle period of a switch included in the power converter. The controller also includes a logic circuit that generates a second signal to control switching of the switch in response to a feedback signal and in response to the first signal. The logic circuit generates the second signal to control a peak switch current of the switch during each switching cycle period according to either a first mode of operation or a second mode of operation. The peak switch current of the switch is varied in the first mode of operation in response to the feedback signal indicating that an output load is greater than a threshold and the peak switch current of the switch is kept at a constant value in the second mode of operation in response to the feedback signal indicating that the output load is less than the threshold. | 10-09-2014 |
20140307485 | TRANSMISSION VOLTAGE LOSS COMPENSATION CIRCUIT, COMPENSATION METHOD, CONTROLLING CHIP AND SWITCHING POWER SUPPLY - In one embodiment, a method of compensating for transmission voltage loss from a switching power supply, can include: (i) receiving a sampling signal that represents an output current of the switching power supply; (ii) delaying the sampling signal to generate a delayed sampling signal; (iii) converting the delayed sampling signal to generate a compensation signal; and (iv) regulating an output voltage of the switching power supply based on the compensation signal to compensate for the transmission voltage loss from the output voltage transmission to a load such that a voltage at the load is maintained as substantially consistent with an expected voltage at the load. | 10-16-2014 |
20140328089 | ON TIME SAMPLING PREVENTION - An example controller circuit includes a feedback sampling circuit, an oscillator, a drive logic, and a false sampling prevention circuit. The feedback sampling circuit generates a sample signal in response to a sampling of a feedback signal. The oscillator generates an on-time signal that transitions from a first logic state to a second logic state during each period of the on-time signal. The drive logic controls a switch to regulate the output of a power converter. The drive logic turns on the switch to end an off-time of the switch in response to the on-time signal transitioning from the first logic state to the second logic state. The false sampling prevention circuit prevents the on-time signal from transitioning from the first logic state to the second logic state to extend the off-time of the switch until a sampling complete signal indicates that sampling of the feedback signal is complete. | 11-06-2014 |
20140362610 | CIRCUITS AND METHODS FOR CONSTANT OUTPUT CURRENT IN A FLYBACK CONVERTER - Flyback converters are disclosed herein. An embodiment of a flyback converter includes a transformer having a primary side and a secondary side. A switch is connected to the primary side of the transformer, wherein the switch controls the current in the primary side of the transformer. A resistance is connected between the switch and a common node. The converter also includes a comparator having a first input and a second, the first input being connected between the switch and the resistor. Driver logic controls the state of the switch, wherein the output of the comparator is coupled to the driver logic. A voltage source is connected to the second input of the comparator. An error amplifier compares the voltage at the second input of the comparator to an adjustment voltage, the output of the error amplifier is coupled to the driver logic. | 12-11-2014 |
20150009719 | SOFT-START SWITCHING POWER CONVERTING APPARATUS - A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus. | 01-08-2015 |
20150023068 | SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus includes a voltage step-up converter that increases input voltage in response to turning on and off of a switching element, a transformer including a primary winding and a secondary winding and the primary winding of which is connected to the output of the voltage step-up converter, a microcontroller that controls the turning on and off of the switching element, an input voltage detection circuit that detects input voltage of the microcontroller, and an intermediate bus voltage detection circuit that detects intermediate bus voltage from the microcontroller. The input voltage detection circuit and the intermediate bus voltage detection circuit are circuits including elements having the same specifications. The microcontroller controls the turning on and off of the switching element based on a result of calculation from voltage values detected by the input voltage detection circuit and the intermediate bus voltage detection circuit. | 01-22-2015 |
20150036392 | Primary Side Regulator - A primary side regulator according to an embodiment includes a power switch connected to a primary winding, a secondary winding configured to be insulated and coupled to the primary winding, a diode connected between the secondary winding and an output terminal, and an auxiliary winding coupled to the primary winding, and insulated and coupled to the secondary winding. The primary side regulator controls a switching operation of the power switch using a voltage obtained by filtering at least one of an estimation voltage signal corresponding to an output voltage of the output terminal and an estimation current signal corresponding to an output current flowing through the diode. | 02-05-2015 |
20150036393 | SYSTEMS AND METHODS FOR REDUCING STANDBY POWER CONSUMPTION OF SWITCH-MODE POWER CONVERTERS - Power conversion system and method. The system includes a first capacitor including a first capacitor terminal and a second capacitor terminal, a second capacitor including a third capacitor terminal and a fourth capacitor terminal, and a plurality of diodes including a first diode, a second diode, a third diode, and a fourth diode. The first diode is coupled to the second diode at a first node, the second diode is coupled to the fourth diode at a second node, the fourth diode is coupled to the third diode at a third node, and the third diode is coupled to the first diode at a fourth node. Additionally, the system includes a fifth diode including a first anode and a first cathode and a sixth diode including a second anode and a second cathode. | 02-05-2015 |
20150070944 | SYSTEMS AND METHODS FOR REGULATING POWER CONVERSION SYSTEMS WITH OUTPUT DETECTION AND SYNCHRONIZED RECTIFYING MECHANISMS - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. The system controller is configured to receive at least an input signal at the first controller terminal, and generate a gate drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to, if the input signal is larger than a first threshold, generate the gate drive signal at a first logic level to turn off the transistor. | 03-12-2015 |
20150103567 | ISOLATED SWITCHING CONVERTER WITH SECONDARY SIDE MODULATION AND CONTROL METHOD - A controller of an isolated switching converter includes an error amplifying circuit, a modulation signal generator, a first comparison circuit, a primary off detection circuit, a secondary logic circuit, an isolation circuit and a primary logic circuit. The error amplifying circuit generates a compensation signal based on the difference between a reference signal and a feedback signal. The first comparison circuit compares the compensation signal with a modulation signal generated by the modulation signal generator and generates a first comparison signal. The primary off detection circuit detects whether the primary switch is off and generates a primary off detection signal. The secondary logic circuit generates a secondary control signal to control the secondary switch based on the first comparison signal and the primary off detection signal. The isolation circuit receives the first comparison signal and generates a synchronous signal electrically isolated from the first comparison signal. The primary logic circuit generates a primary control signal to control the primary switch based on the synchronous signal. | 04-16-2015 |
20150131341 | CONVERTER AND DRIVING METHOD THEREOF - A converter and a driving method thereof are disclosed. The converter includes a transformer, a main switch, a clamp switch, and a switching controller. Here, the switching controller controls a turn-on time of the main switch and a turn-off time of the clamp switch corresponding to an output load. | 05-14-2015 |
20150295500 | SAMPLING FOR DIMMER EDGE DETECTION IN POWER CONVERTER - A controller and a method for controlling a power converter includes a sample block coupled to generate a first, second, and third sample by sampling an input sense signal that is representative of an input voltage of the power converter. An enable signal is asserted when a first difference between the first sample and the second sample exceeds a first threshold. An edge signal is asserted when both the enable signal is asserted and a second difference between the first sample and the third sample exceeds a second threshold. A drive circuit is coupled to output a drive signal in response to the edge signal. The drive signal is for controlling a switch coupled to regulate an output of the power converter. | 10-15-2015 |
20150303812 | DIMMING EDGE DETECTION FOR POWER CONVERTER - A controller for a power converter includes an edge detection circuit and a drive circuit. The edge detection circuit includes a comparator, a count module, and an edge checking module. The comparator is coupled to output a compare signal in response to comparing an input sense signal and a count signal. The input sense signal is representative of an input voltage of the power converter. The count module is coupled to adjust the count signal to track the input sense signal in response to receiving the compare signal. The edge checking module is coupled to output at least one edge signal in response to the compare signal. The drive circuit is coupled to output a drive signal in response to the at least one edge signal. The drive signal is for controlling a switch coupled to regulate an output of the power converter. | 10-22-2015 |
20150311810 | CONTROL CIRCUIT, CONTROL METHOD AND PRIMARY-CONTROLLED FLYBACK CONVERTER USING THE SAME - In one embodiment, a control circuit configured to control a power stage circuit of a primary-controlled flyback converter, can include: (i) a current sense circuit that generates a current sense signal by sampling a primary current; (ii) a voltage sense circuit that generates a voltage sense signal by sampling an auxiliary voltage after a blanking time has elapsed; (iii) a control signal generator that generates a switch control signal according to the voltage sense signal and the current sense signal; and (iv) the switch control signal being configured to control a power switch of the power stage circuit, where the switch control signal is active during a constant on time. | 10-29-2015 |
20150318777 | WAKE UP MANAGEMENT CIRCUIT FOR A SWITCHING CONVERTER AND RELATED WAKE UP METHOD - A switching converter converts an input signal to a regulated output signal using a switch and a transformer with a primary winding and a secondary winding. A wake up management circuit receives a transformer demagnetization signal and forces by wake up pulses the switch on when the switching converter operates in a burst mode. Sampled values of the transformer demagnetization signal are received. A setting circuit sets a first peak value of the current of the primary winding. A comparison circuit compare the sampled values with a voltage threshold and the preceding sampled value. In response thereto, the first peak value of the primary winding current is either maintained or a new peak value is set. | 11-05-2015 |
20150357904 | MOSFET DRIVER WITH PULSE TIMING PATTERN FAULT DETECTION AND ADAPTIVE SAFE OPERATING AREA MODE OF OPERATION - A Safe Operating Area (SOA) adaptive gate driver for a switch mode power converter is disclosed. In response to a detection of a fault condition, the SOA adaptive gate driver may limit the peak current in a power transistor (e.g., power MOSFET) of the power converter by limiting the voltage applied to the gate of the power MOSFET or by limiting the current injected into the gate of the power MOSFET. The limited gate voltage or current may increase the margin between an SOA border and the turn-off locus of the drain voltage and current (V | 12-10-2015 |
20160036336 | SYSTEMS AND METHODS FOR REDUCING ELECTROMAGNETIC INTERFERENCE BY ADJUSTING SWITCHING PROCESSES - System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a signal generator and a driving component. The signal generator is configured to receive a feedback signal associated with an output signal of a power conversion system and a current sensing signal associated with a primary current flowing through a primary winding of the power conversion system and generate a modulation signal based on at least information associated with the feedback signal and the current sensing signal. The driving component is configured to receive the modulation signal and output a drive signal to a switch based on at least information associated with the modulation signal. | 02-04-2016 |
20160056703 | INFORMATION EXCHANGE VIA FLYBACK TRANSFORMER FOR SECONDARY SIDE CONTROL - A power circuit is described that includes a transformer having a primary winding and a secondary winding, a primary side coupled to the primary winding and a secondary side coupled to the secondary winding. The primary side includes a primary element configured to switch-on or switch-off based on a primary voltage or a primary current at the primary side. The secondary side includes a secondary element and a control unit that is isolated from the primary side. The control unit is configured to control the secondary element to transfer secondary side energy, via the transformer, from the secondary side to the primary side to control an amount of primary side energy transferred, via the transformer, from the primary side to the secondary side. | 02-25-2016 |
20160056704 | INFORMATION EXCHANGE VIA FLYBACK TRANSFORMER FOR PRIMARY SIDE CONTROL - A power circuit is described that includes a transformer having a primary winding and a secondary winding, a primary side coupled to the primary winding and a secondary side coupled to the secondary winding. The primary side includes a primary element configured to switch-on or switch-off based at least in part on a primary voltage or a primary current at the primary side. The secondary side includes a secondary element and secondary logic that is isolated from the primary side. The secondary logic is configured to detect a change to an amount of load coupled to the power circuit, and in response to detecting the change to the amount of load, control the secondary element to transfer secondary side energy, via the transformer, from the secondary side to the primary side to control an amount of primary side energy transferred, via the transformer, from the primary side to the secondary side. | 02-25-2016 |
20160072391 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device includes a switching control circuit that generates a switching control signal such that a desired output voltage is generated from an input voltage, a drive circuit that turns on/off an output transistor in accordance with the switching control signal, and an on-pulse stop circuit that generates a pulse stop signal such that the number of ON pulses of the switching control signal is reduced in a state where a load is heavier than a first threshold but is lighter than a second threshold. | 03-10-2016 |
20160105116 | FLYBACK POWER CONVERTER WITH PROGRAMMABLE OUTPUT AND CONTROL CIRCUIT AND CONTROL METHOD THEREOF - The present invention provides a flyback power converter with a programmable output and a control circuit and a control method thereof. The flyback power converter converts an input voltage to a programmable output voltage according to a setting signal, wherein the programmable output voltage switches between different levels. The flyback power converter includes: a transformer circuit, a power switch circuit, a current sense circuit, an opto-coupler circuit, and a control circuit. The control circuit adaptively adjusts an operation signal according to a level of the programmable output voltage, to maintain a same or relatively higher operation frequency of the operation signal when the programmable output voltage switches to a relatively lower level, so as to maintain a phase margin while supplying the same output current. | 04-14-2016 |
20160118901 | SINGLE-STAGE POWER SUPPLY WITH POWER FACTOR CORRECTION AND CONSTANT CURRENT OUTPUT - A switched mode power converter includes a switch, an energy transfer element coupled to the switch, and a controller that includes a delayed ramp generator coupled to generate a delayed ramp signal, an input charge control signal generator coupled to generate an input charge control signal representative of an integral of an input current sense signal and a ratio of an input voltage sense signal to an output voltage sense signal, and a drive signal generator coupled to receive the delayed ramp signal and the input charge control signal, to regulate an output of the switch mode power converter. The drive signal generator produces a drive signal responsive to the input charge control signal and the delayed ramp signal. The drive signal is coupled to control the switch of the switch mode power converter. | 04-28-2016 |
20160134197 | INPUT OVERVOLTAGE PROTECTION USING CURRENT LIMIT - A controller for use in a power converter includes a state selection circuit coupled to receive an input voltage sense signal representative of an input voltage, a switch current sense signal representative of a switch current of a power switch, and a feedback signal representative of an output quantity of the power converter. The state selection circuit is coupled to generate an input voltage signal in response to the input voltage sense signal, an input current signal in response to the switch current sense signal, and an input threshold signal in response to the feedback signal. A state machine circuit is coupled to the state selection circuit to generate a drive signal in response to the input voltage signal, the input current signal, and the input threshold signal to switch the power switch to control a transfer of energy from an input to an output of the power converter. | 05-12-2016 |
20160149499 | SYSTEMS AND METHODS FOR REGULATING POWER CONVERSION SYSTEMS WITH OUTPUT DETECTION AND SYNCHRONIZED RECTIFYING MECHANISMS - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. The system controller is configured to receive at least an input signal at the first controller terminal, and generate a gate drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to, if the input signal is larger than a first threshold, generate the gate drive signal at a first logic level to turn off the transistor. | 05-26-2016 |
20160149500 | HIGH POWER FACTOR PRIMARY REGULATED OFFLINE LED DRIVER - A fly-back type switched current regulator includes a primary transformer winding coupled to receive a rectified DC signal derived from an AC signal. The drain of a power transistor is coupled to the primary winding, with the source of the power transistor coupled to an input of a comparison circuit and a primary transformer winding sense resistor. A control terminal of the power transistor is coupled to an output of the comparison circuit. A capacitor stores a variable reference signal for application at a first capacitor terminal to another input of the differential circuit. The variable reference signal is compared to a winding current signal generated by the sense resistor by the comparison circuit. An injection circuit applies an AC signal derived from the rectified DC signal to a second terminal of the capacitor so as to modulate the stored variable reference signal. The regulator is coupled to drive LEDs. | 05-26-2016 |
20160156273 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES | 06-02-2016 |
20160164424 | METHOD AND APPARATUS FOR INTEGRATED CABLE DROP COMPENSATION OF A POWER CONVERTER - A controller for a power converter includes a switching control circuit to output a drive signal to control switching of a switch to regulate the output power of the power converter, and output a switching signal representative of the drive signal. A cable drop compensator receives the switching signal, and outputs a compensated reference voltage signal to the switching control circuit. The cable drop compensator further includes a switching coefficient calculator to output a switching coefficient signal in response to the switching signal. The switching coefficient signal is representative of a ratio of a load current to a maximum deliverable load current. A voltage compensation calculator outputs the compensated reference voltage signal in response to the switching coefficient signal. The switching control circuit outputs the drive signal in response to the compensated reference voltage signal. | 06-09-2016 |
20180026542 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES | 01-25-2018 |
20190149056 | INPUT VOLTAGE DETECTION FOR FLYBACK CONVERTER | 05-16-2019 |