Patent application number | Description | Published |
20120242237 | SCR DIMMING CIRCUIT AND METHOD - The present invention relates to a silicon-controlled rectifier (SCR) dimming circuit and method for regulating the luminance of a light-emitting diode (LED) load. In one embodiment, an SCR dimming circuit can include: an SCR rectifying circuit having an SCR element that receives an AC power supply, and generates a lack-phase AC voltage; a rectifier bridge that converts the lack-phase AC voltage to a lack-phase DC voltage, where the lack-phase DC voltage is filtered through a filter capacitor to generate a smooth DC voltage; a conduction phase angle signal generator that receives the lack-phase DC voltage and generates a controlling signal indicating a conduction phase angle range of the SCR element; and a dimming signal generator that compares the controlling signal and a slope reference signal to output a dimming signal to control the luminance of the LED load. | 09-27-2012 |
20120256553 | SCR DIMMING CIRCUIT AND METHOD - The present invention relates to an SCR dimming circuit and method for regulating the luminance of an LED load. In one embodiment, an SCR dimming circuit can include: an SCR element that generates a lack-phase AC voltage based on a sinusoidal AC supply; a rectifier bridge that generates a lack-phase DC voltage based on the lack-phase AC voltage; a conduction angle generator that receives the lack-phase DC voltage, and generates a controlling signal representative of a conduction angle of the SCR element; and a dimming signal generator that generates a dimming signal to regulate luminance of the LED load, where the dimming signal generator receives the controlling signal, an adjustable signal, and a clamping voltage, an amplitude of a dimming phase angle range is selected by a fixed signal determined by the clamping voltage, and the dimming phase angle range may be shifted by regulating the adjustable signal. | 10-11-2012 |
20120281448 | POWER FACTOR CORRECTION CIRCUIT - The present invention relates to a power factor correction circuit, that can include: an inductor current detector that generates a sampling voltage signal, and sinusoidal half-wave current and voltage signals based on the sampling voltage signal; a mediate signal generator generating slope voltage and clock signals in response to the sinusoidal half-wave voltage signal, where a frequency of each varies with the sinusoidal half-wave voltage signal; a current modulation circuit receiving the sinusoidal half-wave current signal and a voltage feedback signal representative of a power stage output voltage to generate a regulation signal that is compared against the slope voltage signal to generate a modulation signal; and a logic/driving circuit receiving the modulation and clock signals, and generating a controlling signal that controls a power switch with variable frequency to maintain the inductor current in phase with the sinusoidal half-wave voltage signal and the power stage output voltage constant. | 11-08-2012 |
20130223108 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROLLER AND CONTROL METHOD THEREOF - The present invention relates to a constant voltage constant current (CVCC) controller, and associated control methods. In one embodiment, a CVCC controller for a flyback converter can include: (i) a current controller configured to generate an error signal by comparing an output current feedback signal against a reference current; (ii) a voltage controller configured to receive an output voltage feedback signal and a reference voltage, and to generate a control signal; (iii) a selector configured to control the flyback converter to operate in a first or a second operation mode based on the control signal, and to further generate a constant voltage or a constant current control signal based on the error signal; and (iv) a pulse-width modulation (PWM) controller configured to generate a PWM control signal to control a main switch, and to maintain the output voltage and/or current of the flyback converter as substantially constant. | 08-29-2013 |
20130250629 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROL CIRCUITS AND METHODS WITH IMPROVED LOAD REGULATION - The present invention discloses CVCC circuits and methods with improved load regulation for an SMPS. In one embodiment, the CVCC can include: a voltage feedback circuit to generate an output voltage feedback signal; a current feedback circuit to generate an output current feedback signal; a control signal generating circuit that receives the output voltage feedback signal and the output current feedback signal, and generates a constant voltage/constant current control signal; a first enable signal generating circuit that compares a first reference voltage and the constant voltage/constant current control signal to generate a first enable signal; and a PWM controller that generates a PWM control signal based on the constant voltage/constant current control signal to control a main switch of the flyback SMPS. | 09-26-2013 |
20130342243 | POWER SWITCH DRIVING CIRCUITS AND POWER CONVERTERS THEREOF - In one embodiment, a power switch driving circuit can include: (i) an upper switch having a first power terminal coupled to a voltage source, and a second power terminal coupled to a driving signal; (ii) a lower switch having a first power terminal coupled to the driving signal, and a second power terminal coupled to a first voltage level, where the first voltage level is higher than a first ground potential; (iii) an upper switch driving sub circuit configured to receive a control signal, and to drive the upper switch in response thereto; and (iii) a lower switch driving sub circuit configured to receive the control signal, and to drive the lower switch in response thereto, where the upper and lower switch driving sub circuits are coupled to a second ground potential. | 12-26-2013 |
20140062325 | SCR DIMMING CIRCUIT AND METHOD - The present invention relates to a silicon-controlled rectifier (SCR) dimming circuit and method for regulating the luminance of a light-emitting diode (LED) load. In one embodiment, an SCR dimming circuit can include: an SCR rectifying circuit having an SCR element that receives an AC power supply, and generates a lack-phase AC voltage; a rectifier bridge that converts the lack-phase AC voltage to a lack-phase DC voltage, where the lack-phase DC voltage is filtered through a filter capacitor to generate a smooth DC voltage; a conduction phase angle signal generator that receives the lack-phase DC voltage and generates a controlling signal indicating a conduction phase angle range of the SCR element; and a dimming signal generator that compares the controlling signal and a slope reference signal to output a dimming signal to control the luminance of the LED load. | 03-06-2014 |
20140103895 | COMPENSATION CIRCUIT AND SWITCHING POWER SUPPLY THEREOF - Disclosed are compensation circuits for a switching power supply. In one embodiment, a compensation circuit can include: (i) a transconductance amplifier configured to receive a reference signal and a feedback signal, and to generate an amplifier output signal according to a difference between the reference signal and the feedback signal; (ii) a switching circuit configured to receive the amplifier output signal, where the switching circuit is controllable by a control signal from a switch control circuit; and (iii) a charging circuit coupled to the switching circuit, where the charging circuit is configured to be charged by the amplifier output signal in response to the control signal, and to generate a compensation signal therefrom. | 04-17-2014 |
20140132176 | HIGH-PRECISION LED CONTROL CIRCUIT, METHOD AND LED DRIVER THEREOF - In one embodiment, a light-emitting diode (LED) driver can include: (i) a reference voltage control circuit configured to provide a reference voltage signal in response to an enable signal; (ii) a current control circuit configured to control an output current of the LED driver in response to the reference voltage signal; and (iii) the LED driver being configured to drive an LED load when the enable signal is active. | 05-15-2014 |
20140198540 | INTEGRATED SWITCH MODE POWER SUPPLY CONTROLLER AND SWITCH MODE POWER SUPPLY USING THE SAME - In one embodiment, an integrated switch mode power supply controller can include: a multiplexing pin that receives a detection voltage signal; a switch mode power supply that receives a DC input voltage, and operates in a switching cycle having first, second, and third time intervals; during the first time interval, the detection voltage signal is proportional to the DC input voltage, and a current compensation signal is generated according to the detection voltage signal to obtain a peak inductor current; during the second time interval, the detection voltage signal is proportional to an output voltage of the switch mode power supply, and a discharging duration of current through the inductor is determined based on the detection voltage signal; and during the third time interval, the detection voltage signal is proportional to a voltage across a power transistor of the switch mode power supply. | 07-17-2014 |
20140239835 | SCR DIMMING CIRCUIT AND METHOD - The present invention relates to an SCR dimming circuit and method for regulating the luminance of an LED load. In one embodiment, an SCR dimming circuit can include: an SCR element that generates a lack-phase AC voltage based on a sinusoidal AC supply; a rectifier bridge that generates a lack-phase DC voltage based on the lack-phase AC voltage; a conduction angle generator that receives the lack-phase DC voltage, and generates a controlling signal representative of a conduction angle of the SCR element; and a dimming signal generator that generates a dimming signal to regulate luminance of the LED load, where the dimming signal generator receives the controlling signal, an adjustable signal, and a clamping voltage, an amplitude of a dimming phase angle range is selected by a fixed signal determined by the clamping voltage, and the dimming phase angle range may be shifted by regulating the adjustable signal. | 08-28-2014 |
20140253098 | VOLTAGE PEAK DETECTION CIRCUIT AND DETECTION METHOD - In one embodiment, a voltage peak detection circuit can include: (i) a voltage coupling circuit configured to inductively couple an input inductor voltage of a switching power supply, and to generate a first voltage that represents a DC input voltage of the switching power supply; (ii) a voltage conversion circuit configured to receive the first voltage, and to generate a second voltage that is proportional to the first voltage; and (iii) a holding circuit configured to hold a peak of the second voltage to generate a peak voltage signal that represents peak information of the DC input voltage. | 09-11-2014 |
20140286058 | UNDERVOLTAGE PROTECTION CIRCUIT, UNDERVOLTAGE PROTECTION METHOD AND SWITCHING POWER SUPPLY - In one embodiment, an undervoltage protection circuit for a switching power supply can include: (i) an undervoltage detection circuit that determines whether an input voltage of the switching power supply is in an undervoltage state; (ii) a selection circuit configured to select a first or a second control signal to be provided as a main control signal to a control circuit; (iii) the control circuit being configured, in response to the main control signal being the first control signal, to control a switching operation of a power transistor in the switching power supply such that an output voltage of the switching power supply is maintained as substantially stable; and (iv) the control circuit being configured, in response to the main control signal being the second control signal, to control the switching operation of the power transistor to reduce an input power of the switching power supply. | 09-25-2014 |
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 |
20140307486 | CAPACITOR DISCHARGING METHOD AND DISCHARGING CIRCUIT THEREOF - In one embodiment, a method of controlling a capacitor discharge for a switching power supply, can include: (i) generating a first voltage signal from a voltage at an X capacitor that is coupled between input terminals of the switching power supply; (ii) activating a detection signal in response to the first voltage signal being inactive for a duration of a predetermined time interval, where the detection signal being activated indicates a cut-off of the input terminals; and (iii) at least partially discharging the X capacitor after the cut-off and in response to activation of the detection signal. | 10-16-2014 |
20140313786 | CONTROLLING CIRCUIT AND AC/DC CONVERTER THEREOF - In one embodiment, a controlling circuit configured for an AC/DC converter that receives an AC voltage supply, can include: (i) a compensation signal generator configured to generate a compensation signal that follows an error between an output signal from the AC/DC converter and an expected converter output signal during a first time interval of a half period of the AC voltage supply, the compensation signal being substantially constant during a remaining time interval of the half period; and (ii) a controlling signal generator configured to generate a controlling signal based on the compensation signal to maintain the output signal as substantially consistent with the expected converter output signal. | 10-23-2014 |
20140340946 | POWER SWITCH DRIVING CIRCUITS AND POWER CONVERTERS THEREOF - In one embodiment, a power switch driving circuit can include: (i) an upper switch having a first power terminal coupled to a voltage source, and a second power terminal coupled to a driving signal; (ii) a lower switch having a first power terminal coupled to the driving signal, and a second power terminal coupled to a first voltage level, where the first voltage level is higher than a first ground potential; (iii) an upper switch driving sub circuit configured to receive a control signal, and to drive the upper switch in response thereto; and (iii) a lower switch driving sub circuit configured to receive the control signal, and to drive the lower switch in response thereto, where the upper and lower switch driving sub circuits are coupled to a second ground potential. | 11-20-2014 |
20150055383 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROLLER AND CONTROL METHOD THEREOF - The present invention relates to a constant voltage constant current (CVCC) controller, and associated control methods. In one embodiment, a CVCC controller for a flyback converter can include: (i) a current controller configured to generate an error signal by comparing an output current feedback signal against a reference current; (ii) a voltage controller configured to receive an output voltage feedback signal and a reference voltage, and to generate a control signal; (iii) a selector configured to control the flyback converter to operate in a first or a second operation mode based on the control signal, and to further generate a constant voltage or a constant current control signal based on the error signal; and (iv) a pulse-width modulation (PWM) controller configured to generate a PWM control signal to control a main switch, and to maintain the output voltage and/or current of the flyback converter as substantially constant. | 02-26-2015 |
20150062979 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROL CIRCUITS AND METHODS WITH IMPROVED LOAD REGULATION - The present invention discloses CVCC circuits and methods with improved load regulation for an SMPS. In one embodiment, the CVCC can include: a voltage feedback circuit to generate an output voltage feedback signal; a current feedback circuit to generate an output current feedback signal; a control signal generating circuit that receives the output voltage feedback signal and the output current feedback signal, and generates a constant voltage/constant current control signal; a first enable signal generating circuit that compares a first reference voltage and the constant voltage/constant current control signal to generate a first enable signal; and a PWM controller that generates a PWM control signal based on the constant voltage/constant current control signal to control a main switch of the flyback SMPS. | 03-05-2015 |