Patent application number | Description | Published |
20090279214 | PROTECTION APPARATUS AND METHOD FOR A POWER CONVERTER - A power converter uses a PWM controller to provide a driver output to modulate the duty of the power converter. A protection apparatus and method compare a current sense input of the PWM controller with a reference voltage to assert a signal representing failure, count the number of cycles where the signal representing failure is asserted, and reset an enable signal to inhibit the driver output if the signal representing failure is asserted in several cycles. | 11-12-2009 |
20100315843 | METHOD OF DETECTION FOR OUTPUT SHORT CIRCUIT OF A FLYBACK POWER SUPPLY - Disclosed are methods of detection for output short circuit of a flyback power supply, which detect the current sense signal provided by a current sense resistor serially connected to a power switch of the flyback power supply, and thus quickly identify whether or not the flyback power supply suffers output short circuit. | 12-16-2010 |
20100320989 | PROTECTION APPARATUS AND METHOD FOR AN ISOLATED TYPE POWER SUPPLY - An isolated type power supply includes a transformer, and a power switch and a current sense resistor serially connected to a primary coil of the transformer, and a protection apparatus and method monitor a control signal which is used to switch the power switch in normal operation, and trigger a signal to stop the power from switching when the control signal becomes greater than a threshold. This protection apparatus and method can more quickly detect short circuit of the current sense resistor, and prevent the isolated type power supply from overcurrent impact. | 12-23-2010 |
20110051463 | APPARATUS AND METHOD FOR STANDBY POWER REDUCTION OF A FLYBACK POWER CONVERTER - An apparatus and method for a flyback power converter reduce the standby output voltage of the flyback power converter by switching the reference voltage provided by a shunt regulator of the flyback power converter or the ratio of voltage divider resistors of the shunt regulator, to reduce the standby power consumption by an output feedback circuit of the flyback power converter, the shunt regulator, and the voltage divider resistors, and thereby the power loss of the flyback power converter in standby mode. | 03-03-2011 |
20110249476 | VOLTAGE DETECTOR AND PROTECTION APPARATUS USING THE SAME - A voltage detector includes a zener diode having a cathode connected to a detect terminal of the voltage detector, a junction field effect transistor having an input terminal connected to an anode of the zener diode, and a resistor connected between an output terminal and a control terminal of the junction field effect transistor. When the voltage on the detect terminal is higher than the breakdown voltage of the zener diode, the junction field effect transistor produces a current flowing through the resistor, and thereby a detection signal can be obtained from the voltage across the resistor. | 10-13-2011 |
20120086480 | CIRCUIT AND METHOD FOR SUB-HARMONIC ELIMINATION OF A POWER CONVERTER - A circuit and method are provided for a power converter to select one from a plurality of current limit signals as a final current limit signal according to the present duty ratio of a power switch for the pulse width modulation of the next cycle, so that the duty ratio of the power switch in the next cycle is prevented from acute variation to eliminate sub-harmonic which otherwise may happen. | 04-12-2012 |
20120194162 | PULSE WIDTH MODULATION CONTROLLER AND METHOD FOR OUTPUT RIPPLE REDUCTION OF A JITTERING FREQUENCY SWITCHING POWER SUPPLY - A pulse width modulation controller and method for output ripple reduction of a jittering frequency switching power supply detect the current of a power switch of the switching power supply to generate a current sense signal, and adjust the gain or the level of the current sense signal according to the switching frequency of the power switch to adjust the on time of the power switch, to reduce the output ripple of the switching power supply caused by the jittering frequency of the switching power supply. | 08-02-2012 |
20120194227 | JITTERING FREQUENCY CONTROL CIRCUIT AND METHOD FOR A SWITCHING MODE POWER SUPPLY - A jittering frequency control circuit and method for a switching mode power supply enlarge the uttering frequency range of the switching frequency of the switching mode power supply when the switching mode power supplier enters a frequency reduction mode, to improve the electro-magnetic interference of the switching mode power supply operating with the frequency reduction mode. | 08-02-2012 |
Patent application number | Description | Published |
20090302827 | Sensing circuit and method for a flyback converter - A flyback converter includes a transformer to convert an input voltage into an output voltage, a control circuit senses a primary current of the transformer to generate a current sense signal, and a sensing circuit is configured to sense a variation of the current sense signal between two time points for extracting the input voltage information therefrom. | 12-10-2009 |
20090303756 | Maximum output power control of a flyback converter - A method and apparatus for a flyback converter estimate the next value of the current limit for the flyback converter according to a present current limit value to achieve the maximum output power control of the flyback converter. An arithmetic circuit is used to calculate the next current limit value according three parameters, the present current limit value, the value of the current sense signal taken after a first time period counting from the instant when the present duty is triggered, and the variation of the current sense signal during a second time period, thereby narrowing the tolerance of the output power from the flyback converter. | 12-10-2009 |
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 |
20110012554 | APPARATUS AND METHOD FOR IMPROVING THE STANDBY EFFICIENCY OF A CHARGER, AND ULTRA LOW STANDBY POWER CHARGER - A charger has two pins for connecting with a battery therebetween, and an apparatus and method are proposed to determine to wake up or turn off the charger according to a voltage or a current detected from the two pins, to reduce the standby power consumption of the charger. | 01-20-2011 |
20110018609 | TEMPERATURE COMPENSATION IN OUTPUT FEEDBACK OF A FLYBACK POWER CONVERTER - A secondary circuit of a flyback power converter has a resistor network to monitor the output current of the flyback power converter, so as to generate a voltage to apply to a base of a bipolar junction transistor to thereby provide a collector signal for output feedback. The resistor network has a temperature-dependent resistance to compensate the temperature dependence of the base-emitter voltage imparted to the output current and thereby stable the output current. | 01-27-2011 |
20110022867 | APPARATUS AND METHOD FOR REDUCING THE STANDBY POWER CONSUMPTION OF A DISPLAY, AND DISPLAY WITH LOW STANDBY POWER CONSUMPTION - A display includes a power supply system using a power controller to switch a power switch to control power delivery, and an image scalar receiving a supply voltage and a supply current from the power supply system. An apparatus and method are proposed to determine a control signal in a standby mode by monitoring the supply voltage or the supply current, to wake up or turn off the power controller to reduce the switching times of the power switch in the standby mode, thereby reducing the switching loss of the power switch and the standby power consumption of the display. | 01-27-2011 |
20120013367 | Power stage control circuit - The present invention discloses a power stage control circuit including: a driver circuit for controlling a power stage according to an error amplified signal; an error amplifier circuit for comparing a feedback voltage at a feedback terminal with a reference signal to generate the error amplified signal; a current generator circuit coupled to the feedback terminal for generating a fault detection current flowing to the feedback terminal; and a feedback terminal short detection circuit for generating a fault signal to stop the operation of the power stage when the feedback voltage is smaller than a short-circuit threshold voltage or when the fault detection current is larger than a short-circuit threshold current. | 01-19-2012 |
Patent application number | Description | Published |
20080278973 | Apparatus and method for providing multiple functions and protections for a power converter - A power converter has a transformer including a primary winding connected between a power input and a power switch, the power switch is switched to deliver power from the power input to a power output, an auxiliary winding provides an induced voltage in such a manner that when the power switch is at a first switch state, the induced voltage reflects an input information of the power converter, and when the power switch is at a second switch state, the induced voltage reflects an output information of the power converter. Two detection signals are generated from the input and output information, respectively, to implement multiple functions and protections. | 11-13-2008 |
20080279324 | Frequency jittering control for varying the switching frequency of a power supply - A frequency jittering circuit modulates a hysteretic band of an oscillator such that the clock generated by the oscillator has a jitter frequency, and thus a switching mode power supply operative on the clock will have a jittering switching frequency. | 11-13-2008 |
20080298099 | Apparatus and method for reducing the die area of a PWM controller - An apparatus and method for reducing the die area of a PWM controller include a protection circuit triggered by a fault index signal for counting, and the counting time is provided for a delay time required by fault verification. Therefore, fault detection circuits can be eliminated and the purpose of reducing the die area can be achieved. | 12-04-2008 |
20080310192 | Output power limit for a switching mode power converter by a current limit signal having a multi-slope waveform - A current limit signal having a multi-slope waveform is provided for a power converter that has a power switch switched to convert an input voltage to an output voltage, for output power control more preciously. The current flowing through the power switch has a maximum value being a function of a duty cycle of the power switch when the power converter operates at a constant output power condition. The current limit signal is generated according to the function, and is compared with a sensing signal produced from the current flowing through the power switch, so as to turn off the power switch if the sensing signal is not lower than the current limit signal. | 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 |
Patent application number | Description | Published |
20160079874 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - A constant on-time isolated converter comprising a transformer is disclosed. The transformer primary side connects to an electronic switch and secondary-side connects to a load and a processor. The processor connects to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal. The driver receives control signal through the coupling element and accordingly changes the electronic switch ON/OFF state, regulating output voltage and current via the transformer, where the electronic switch ON/OFF duration is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed response to load transient. | 03-17-2016 |
20160079875 | CONSTANT ON TIME COT CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
20160079876 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
20160079877 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
20160079878 | CONSTANT ON TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |