Patent application number | Description | Published |
20080258651 | METHOD AND SYSTEM FOR OPEN LAMP PROTECTION - A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity. | 10-23-2008 |
20090153127 | METHOD AND APPARATUS FOR EXTERNAL CONTROL MODE STEP DOWN SWITCHING REGULATOR - A switching regulator integrated circuit (IC) is disclosed that includes a switch circuit that further includes a first switch and a second switch, a mode selector circuit controlled by external circuitry to select between a first mode and a second mode, and a control circuit. In response to a feedback signal from the switch circuit, when the first mode is selected, the control circuit toggles the first switch and the second switch ON and OFF alternately at a fixed first frequency. When a second mode is selected, the control circuit causes the second switch to turn OFF completely and the first switch to switch ON and OFF at a variable second frequency. | 06-18-2009 |
20100097045 | Single inductor multiple output power supply - Single inductor based switching regulators are disclosed herein. In one embodiment, a switching regulator can include: (i) output switches coupled to a common inductor node and to a corresponding output supply node, where each output supply node has a voltage converted from an input voltage received at an input supply node; (ii) an inductor coupled to the common inductor node and to first and second input switches, where the first input switch is coupled to ground, and the second input switch is coupled to the input supply node, the first and second switches controlling charge through the inductor; and (iii) a control circuit receiving feedback signals indicating output voltages on the output supply nodes, the control circuit controlling the output switches for regulation of the output voltages in response to the feedback signals. | 04-22-2010 |
20100124086 | High efficiency synchronous reectifiers - Methods and circuits for synchronous rectifier control are disclosed herein. In one embodiment, a synchronous rectifier control circuit can include: (i) a first sense circuit to sense a voltage between first and second power terminals of a synchronous rectifier device prior to a turn-on of the device, where a timing of the turn-on of the synchronous rectifier device is adjustable using a first control signal generated from the first sense circuit; (ii) a second sense circuit configured to sense a voltage between the first and second power terminals after a turn-off of the device, where a timing of the turn-off of the device is adjustable using a second control signal generated from the second sense circuit; and (iii) a driver control circuit configured to receive the first and second control signals, and to generate therefrom a gate control signal configured to drive a control terminal of the synchronous rectifier device. | 05-20-2010 |
20100213910 | METHOD AND APPARATUS FOR EXTERNAL CONTROL MODE STEP DOWN SWITCHING REGULATOR - A switching regulator integrated circuit (IC) is disclosed that includes a switch circuit that further includes a first switch and a second switch, a mode selector circuit controlled by external circuitry to select between a first mode and a second mode, and a control circuit. In response to a feedback signal from the switch circuit, when the first mode is selected, the control circuit toggles the first switch and the second switch ON and OFF alternately at a fixed first frequency. When a second mode is selected, the control circuit causes the second switch to turn OFF completely and the first switch to switch ON and OFF at a variable second frequency. | 08-26-2010 |
20100244788 | Power regulation for large transient loads - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a power supply can include: (i) an input capacitor coupled to an input terminal that is coupled to a power source, where the power source provides power that is constrained by a predetermined limit; (ii) an output capacitor coupled to an output terminal that is coupled to a load, where the load has a first load condition or a second load condition; (iii) a first regulator to convert an input voltage at the input terminal to an output voltage at the output terminal to power the load; (iv) a second regulator coupled to the first regulator; and (v) an energy storage element coupled to the second regulator, where the second regulator delivers energy from the energy storage element to the first regulator to maintain regulation of an output voltage at the output terminal when in the second load condition. | 09-30-2010 |
20100301827 | Control for regulator fast transient response and low EMI noise - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a switching regulator can include: (i) a filter network coupled to an output terminal, where an output voltage is generated at the output terminal from an input source; (ii) an active switch to connect the input source to the filter network by periodically operating between on and off states over a switching period, where a duty cycle of the on state relative to the switching period is modulated based on a PWM control signal; (iii) a comparator receiving an output feedback signal, a hysteresis signal, and a reference level, and providing the PWM control signal therefrom; and (iv) a hysteresis programming circuit generating the hysteresis signal, and a ramp control signal, where the hysteresis signal is programmed based on conditions at the input source and the output voltage to achieve a pseudo constant frequency operation. | 12-02-2010 |
20100308654 | Mixed mode control for switching regulator with fast transient responses - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a switching regulator controller can include: (i) a first feedback circuit for sensing an output of a switching regulator to compare against a regulation reference, and to generate a control signal suitable for matching the output of the switching regulator to the regulation reference during a steady state operation of the switching regulator; and (ii) a second feedback circuit for sensing a regulation difference between the output and the regulation reference, and to generate an adjustment signal in response to the regulation difference, where the adjustment signal adjusts the control signal under transient conditions to improve transient responses of said switching regulator. | 12-09-2010 |
20110254143 | Chip package structure and method of making the same - Methods and structures related to packaging a chip are disclosed. In one embodiment, a chip package structure includes: (i) a chip having a plurality of first and second contact pads thereon; (ii) a lead frame having a plurality of pins for external connection to the package structure, where the chip is disposed on the lead frame; (iii) a plurality of first bonding wires for connecting the first contact pads to the lead frame; and (iv) a plurality of second bonding wires for connecting the second contact pads to the plurality of pins on the lead frame. | 10-20-2011 |
20110258305 | Servlet API and Method for XMPP Protocol - A communication system and method include a server hosting an interactive voice response or self-help application in a Java virtual machine. In order to leverage the advantages and facilities of the Java servlet model, a Java XMPP (Extensible Messaging and Presence Protocol) servlet container is provided for the server so that the communication application can be programmed with objects defined by an XMPP servlet API, as well as objects defined by the standards-based Java EE platform such as HTTP and SIP servlets, in order to service an XMPP client. In addition to the generic class objects of the Java servlet model, the API also provides a set of XMPP-specific class objects. The Java XMPP servlet container includes a network point at a transport level for handling network connections, an XMPP service layer for managing XMPP sessions and streams, and an application layer for managing XMPP stanzas. | 10-20-2011 |
20110258597 | Unified Framework and Method for Call Control and Media Control - A communication system and method include a server hosting an interactive voice response or self-help application in a Java virtual machine. The communication application is programmed with a unified communication API, which is provided by a unified application framework. The API provides a set of unified class objects for call control and media control. The unified class objects are constructed from class object primitives of individual standards-based Java call control API and media control API. The constructs are a structured and restricted set conforming to the object model of the application and its states. The API has a unified event handler for both call and media controls and dispatches events to the application based on the type of event and the application state of the object model. | 10-20-2011 |
20120016932 | System And Method For Telephony And Communication Services With Message-Based API - A communication application server is provided with a unified framework for call control and media control. The framework supports a unified API having class objects and functions conforming to a telephony object model. The class objects are invoked and manipulated by a finite set of commands and an application program essentially issues a series of such commands to operate the communication application server. More particularly, an API server on the communication application server defining a messaging API protocol enables an application script to pass commands remotely to the communication application server to operate it. This allows application scripts to be processed remotely by appropriate scripting engines. In this way, application scripting is decoupled from the operation of the communication application server, which only needs to focus on providing basic communication services. | 01-19-2012 |
20120112716 | POWER REGULATION FOR LARGE TRANSIENT LOADS - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a power supply can include: (i) an input capacitor coupled to an input terminal that is coupled to a power source, where the power source provides power that is constrained by a predetermined limit; (ii) an output capacitor coupled to an output terminal that is coupled to a load, where the load has a first load condition or a second load condition; (iii) a first regulator to convert an input voltage at the input terminal to an output voltage at the output terminal to power the load; (iv) a second regulator coupled to the first regulator; and (v) an energy storage element coupled to the second regulator, where the second regulator delivers energy from the energy storage element to the first regulator to maintain regulation of an output voltage at the output terminal when in the second load condition. | 05-10-2012 |
20120153922 | CONTROL FOR REGULATOR FAST TRANSIENT RESPONSE AND LOW EMI NOISE - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a switching regulator can include: (i) a filter network coupled to an output terminal, where an output voltage is generated at the output terminal from an input source; (ii) an active switch to connect the input source to the filter network by periodically operating between on and off states over a switching period, where a duty cycle of the on state relative to the switching period is modulated based on a PWM control signal; (iii) a comparator receiving an output feedback signal, a hysteresis signal, and a reference level, and providing the PWM control signal therefrom; and (iv) a hysteresis programming circuit generating the hysteresis signal, and a ramp control signal, where the hysteresis signal is programmed based on conditions at the input source and the output voltage to achieve a pseudo constant frequency operation. | 06-21-2012 |
20120209936 | COMMUNICATION CIRCUIT AND METHOD UTILIZING A SINGLE COMMUNICATION LINE - The present invention relates to a communication circuit and method utilizing a single communication line. In one embodiment, a communication circuit can include: a host apparatus having a host sub-circuit and a host port; and a slave apparatus having a slave sub-circuit and a slave port, where the host and slave apparatuses are coupled by the host and slave ports via the single communication line, when the slave apparatus is in a normal working condition, the host sub-circuit receives a first controlling signal, and generates an output controlling signal for the slave sub-circuit, which generates a second controlling signal, when the slave apparatus is in an abnormal working condition, the slave sub-circuit receives a first feedback signal, and generates a feedback controlling signal for the host apparatus, and generates a second feedback signal that regulates the first controlling signal such that the slave apparatus recovers to the normal working condition. | 08-16-2012 |
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 |
20120313219 | CHIP PACKAGE STRUCTURE AND METHOD OF MAKING THE SAME - Methods and structures related to packaging a chip are disclosed. In one embodiment, a chip package structure includes: (i) a chip having a plurality of first and second contact pads thereon; (ii) a lead frame having a plurality of pins for external connection to the package structure, where the chip is disposed on the lead frame; (iii) a plurality of first bonding wires for connecting the first contact pads to the lead frame; and (iv) a plurality of second bonding wires for connecting the second contact pads to the plurality of pins on the lead frame. | 12-13-2012 |
20130002159 | CONTROLLING CIRCUIT FOR AN LED DRIVER AND CONTROLLING METHOD THEREOF - The present invention relates to a high efficiency light-emitting diode (LED) driver that can include a controller, an LED apparatus, an LED current sensing circuit, and a power switch. The LED current sensing circuit may be used to generate a feedback signal indicative of LED current. The controller may be coupled to the LED current sensing circuit to receive the feedback signal and generate a driving signal. The power switch may be used to operate in periodic on and off conditions to drive the LED apparatus and maintain a driving current of the LED apparatus that is substantially constant. | 01-03-2013 |
20130063102 | CONSTANT TIME CONTROLLER AND CONTROLLING METHOD FOR SWITCHING REGULATOR - The present invention relates to a constant time controller, controlling method thereof, and a switching regulator. In one embodiment, a controlling method for a switching regulator, can include: (i) detecting an output voltage and an inductor current of the switching regulator; (ii) determining if there is a transient change on a load of the switching regulator by using the output voltage and a first reference voltage; (iii) generating a control signal using the output voltage, the inductor current, and a second reference voltage; (iv) controlling a switch of the switching regulator to maintain the output voltage substantially constant when no transient change is determined on the load; and (v) deactivating the control signal to keep the inductor current changing along with a variation tendency of an output current of the switching regulator when a transient change is determined on the load. | 03-14-2013 |
20130175936 | HIGH EFFICIENCY LED DRIVER AND DRIVING METHOD THEREOF - The present invention relates to a high efficiency LED driver and driving method thereof. In one embodiment, a high efficiency LED driving method configured for a LED device can include: (i) receiving a DC bus voltage and generating a driving voltage for the LED device through a power switch; (ii) comparing the DC bus voltage against a sum of the driving voltage and a first reference voltage; (iii) where when the DC bus voltage is greater than the sum of the driving voltage and the first reference voltage, generating a first output current; (iv) where when the DC bus voltage is greater than the driving voltage and less than the sum of the driving voltage and the first reference voltage, generating a second output current; and (v) matching an average current of the first output current and the second output current with a corresponding driving current. | 07-11-2013 |
20130181626 | HIGH EFFICIENCY LED DRIVER AND DRIVING METHOD THEREOF - The present invention relates to a high efficiency LED driver, and driving methods thereof. In one embodiment, a high efficiency LED driving method can include: (i) receiving an AC input voltage to obtain an absolute value thereof; (ii) receiving a DC bus voltage, and driving the LED device through a power switch; (iii) generating a first reference voltage according to a driving current and an expected driving current; (iv) comparing the absolute value against a sum of a driving voltage and the first reference voltage; (v) when the absolute value is greater than the sum of the driving voltage and the first reference voltage, turning off the power switch; and (vi) when the absolute value is greater than the driving voltage but less than the sum of the driving voltage and the first reference voltage, turning on the power switch to generate an output current. | 07-18-2013 |
20130293213 | START-UP CIRCUIT AND METHOD THEREOF - Methods and circuits related to power regulator start-up are disclosed. In one embodiment, a start-up circuit can include: (i) a delay circuit having a resistor and a capacitor, where the capacitor is coupled between ground and a common node; and (ii) a control chip that receives a reference voltage, and includes an input pin coupled to an input source, an output pin supplying power for a device, and a multiplexed pin coupled to the resistor at the common node to receive an enable signal. The start-up circuit outputs an electrical signal at the output pin based on a comparison of a voltage at the multiplexed pin against the reference voltage, and after a delay time determined by the capacitor and the reference voltage. The voltage at the multiplexed pin can increase continuously with a rising slope determined by input current flowing through the multiplexed pin during a start-up process. | 11-07-2013 |
20130301309 | CONTROL CIRCUITS AND CONTROL METHODS FOR FLYBACK CONVERTERS AND AC-DC POWER CONVERTERS THEREOF - The present invention relates to control circuits and methods for a flyback converter and AC-DC power converters thereof. In one embodiment, a control circuit can include: (i) a turn-on signal generating circuit that is configured, in each switching cycle, to receive a drain-source voltage of a power switch of the flyback converter, and to activate a turn-on signal to turn on the power switch when the drain-source voltage reaches a valley value; (ii) a turn-off signal generating circuit that is configured, in each switching cycle, to activate a turn-off signal to turn off the power switch based on a power switch feedback error signal after a power switch conducting time interval has elapsed; and (iii) where input current and voltages of the flyback converter can be maintained as substantially in phase, and an output electrical signal of the flyback converter can be maintained as substantially constant. | 11-14-2013 |
20130313989 | HIGH EFFICIENCY LED DRIVERS WITH HIGH POWER FACTOR - The present invention relates to a high efficiency, high power factor LED driver for driving an LED device. In one embodiment, an LED driver can include: an LED current detection circuit coupled to the LED device, and configured to generate a feedback signal that represents an error between a driving current and an expected driving current of the LED device; a power stage circuit, where a first power switch terminal is coupled to a first input voltage, and a second power switch terminal is coupled to ground; and a control circuit configured to generate a control signal according to the feedback signal and a drain-source voltage of the power switch, where the control signal, in each switch period, turns on the power switch when the drain-source voltage reaches a low level, and turns off the power switch after a fixed time interval based on the feedback signal. | 11-28-2013 |
20130329463 | HIGH EFFICIENCY AND FAST RESPONSE AC-DC VOLTAGE CONVERTERS - The present invention discloses circuits and methods for high efficiency and fast response AC-DC voltage converters. In one embodiment, an AC-DC voltage converter can include: (i) a first stage voltage converter having an isolated topology with a power factor correction function, where the first stage voltage converter is configured to convert an AC input voltage to a series-connected N branches of first stage voltages, where N is a positive integer of at least two; (ii) a second stage voltage converter having a non-isolated topology, where the second stage voltage converter is configured to convert one of the N branches of the first stage voltages to a second stage voltage; and (iii) where the second stage voltage and a remaining of the N branches of the first stage voltages are configured to be series-connected and converted to a DC output voltage. | 12-12-2013 |
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 |
20140021874 | HIGH-EFFICIENCY LED DRIVER AND DRIVING METHOD - Disclosed are LED driver circuits, and methods of driving LED loads. In one embodiment, an LED driver can include: (i) an SCR coupled to an AC power supply, and configured to generate a DC voltage through a first rectifier circuit; (ii) a first stage conversion circuit having an isolated topology with power factor correction, where the first stage conversion circuit is configured to convert the DC voltage to a first output voltage; (iii) where the first stage conversion circuit includes a transformer having a primary side coupled to the DC voltage, and a secondary side coupled to the first output voltage through a second rectifier circuit; and (iv) a second stage conversion circuit having a non-isolated topology, where the second stage conversion circuit is configured to convert the first output voltage to an output current configured to drive an LED load based on a conducting angle of the SCR. | 01-23-2014 |
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 |
20140063861 | AC-DC VOLTAGE CONVERTER WITH LOW STANDBY POWER CONSUMPTION AND CONTROL METHOD THEREOF - Disclosed are AC-DC voltage converter circuits and methods for low standby power consumption. In one embodiment, a method can include: (i) detecting operating states of an input power supply, where the input power supply is received by a safety capacitor and provided to a switching power supply circuit after being rectified and filtered; (ii) removing a phantom load when the input power supply operates in a normal operating state; (iii) loading the phantom load when the input power supply operates in an under voltage lock out state; and (iv) when the input power supply operates in the under voltage lock out state, using energy stored in the safety capacitor to supply power to a load of the switching power supply circuit and the phantom load, and disabling a power stage circuit until a voltage of the safety capacitor is reduced to less than a safety threshold value. | 03-06-2014 |
20140070390 | MULTI-CHIP PACKAGING STRUCTURE AND METHOD - Disclosed are multi-chip packaging structures and methods. In one embodiment, a multi-chip packaging structure can include: (i) N chips, where N is an integer of at least two, and where an upper surface of each chip comprises a plurality of pads; (ii) a lead frame with a chip carrier and a plurality of pins, where the N chips are stacked in layers on the chip carrier, and where a chip in an upper layer partially covers a chip in a lower layer such that the plurality of pads of the lower layer chip are exposed; (iii) a plurality of first bonding leads configured to connect pads on one chip to pads on another chip; and (iv) a plurality of second bonding leads configured to connect pads on at least one chip to the plurality of pins for external connection to the multi-chip packaging structure. | 03-13-2014 |
20140077867 | BIAS VOLTAGE GENERATING CIRCUIT AND SWITCHING POWER SUPPLY THEREOF - Disclosed herein are bias voltage generating circuits configured for switching power supplies, and associated control methods. In one embodiment, a bias voltage generating circuit can include: (i) a first control circuit configured to compare a drain-source voltage of a switch against a bias voltage; (ii) a capacitor, with the bias voltage across the capacitor; (iii) a second control circuit configured to control the switch, and that is enabled when the bias voltage is at least as high as an expected bias voltage; (iv) the first control circuit being configured to control the capacitor to charge when the drain-source voltage of the switch is greater than the bias voltage; and (v) the bias voltage being less than an overvoltage protection voltage when the capacitor charges, and where the overvoltage protection voltage comprises a voltage that is a predetermined amount higher than the expected bias voltage. | 03-20-2014 |
20140091778 | CONSTANT TIME CONTROLLER AND CONTROLLING METHOD FOR A SWITCHING REGULATOR - In one embodiment, a controlling method for a switching regulator, can include: (i) detecting an output voltage and an inductor current of the switching regulator; (ii) determining if there is a transient change on a load of the switching regulator by using the output voltage and a first reference voltage; (iii) generating a control signal using the output voltage, the inductor current, and a second reference voltage; (iv) controlling a switch of the switching regulator to maintain the output voltage substantially constant when no transient change is determined on the load; and (v) deactivating the control signal to keep the inductor current changing along with a variation tendency of an output current of the switching regulator when a transient change is determined on the load. | 04-03-2014 |
20140112031 | CONTROL AND DRIVE CIRCUIT AND METHOD - Disclosed herein are control and drive circuits and methods for synchronous rectification switching power supply bias voltage generating circuits configured for a switching power supply. In one embodiment, a control and drive circuit can include: (i) a primary side switch controller configured to generate a primary side switch control signal; (ii) a logic circuit configured to generate a first control signal based on the primary side switch control signal; (iii) a converting circuit configured to generate a second control signal based on the first control signal; and (iv) a synchronous rectifier switch controller configured to generate a synchronous rectifier switch control signal based on the second control signal such that phases of the primary side switch control signal and the synchronous rectifier switch control signal are the same or inverse based on a topology of the synchronous rectification switching power supply. | 04-24-2014 |
20140139196 | LOW-NOISE MULTI-OUTPUT POWER SUPPLY CIRCUIT AND CONTROL METHOD THEREOF - Disclosed herein are low-noise multi-output power supply circuits and methods. In one embodiment, a method of controlling a low-noise multi-output power supply circuit, can include: (i) detecting operation states of each of a plurality of switch mode power supplies; (ii) generating a frequency modulation signal to control an operating frequency of a switch mode power supply to be substantially equal to a main frequency signal when the switch mode power supply is detected to operate in a heavy-load steady state; and (iii) controlling the operating frequency of the switch mode power supply to be independent of the main frequency signal when the switch mode power supply is detected to operate in a light-load or a dynamic state. | 05-22-2014 |
20140140105 | HIGH EFFICIENCY AND FAST RESPONSE AC-DC VOLTAGE CONVERTERS - The present invention discloses circuits and methods for high efficiency and fast response AC-DC voltage converters. In one embodiment, an AC-DC voltage converter can include: (i) a first stage voltage converter having an isolated topology with a power factor correction function, where the first stage voltage converter is configured to convert an AC input voltage to a series-connected N branches of first stage voltages, where N is a positive integer of at least two; (ii) a second stage voltage converter having a non-isolated topology, where the second stage voltage converter is configured to convert one of the N branches of the first stage voltages to a second stage voltage; and (iii) where the second stage voltage and a remaining of the N branches of the first stage voltages are configured to be series-connected and converted to a DC output voltage. | 05-22-2014 |
20140145679 | HIGH EFFICIENCY BI-DIRECTIONAL DC CONVERTER AND CONTROL METHOD THEREOF - Disclosed herein are bi-directional DC converter circuits and control methods. In one embodiment, a method of controlling a bi-directional DC converter, can include: (i) detecting whether there is an input power supply at an input port, where the bi-directional DC converter comprises a single magnetic element; (ii) operating the bi-directional DC converter in a first operation mode to charge a battery when the input power supply is detected at the input port; (iii) operating the bi-directional DC converter in a second operation mode to transfer power from the battery to an output port for a load when the input power supply is not detected at the input port; and (iv) transferring power through the single magnetic element in both the first operation mode and the second operation mode. | 05-29-2014 |
20140152239 | SELF-ADAPTIVE INPUT POWER CHARGER AND METHOD FOR CONTROLLING INPUT CURRENT OF CHARGER - Disclosed herein are circuits and methods for limiting a charger input current. In one embodiment, a self-adaptive input power charger for charging a battery, can include: (i) a power stage circuit configured to receive an external input power supply that supplies an input voltage and an input current to the charger; (ii) a comparison circuit configured to generate a comparison result indicating that the input power supply has entered a current-limiting state when the input voltage is less than a first reference voltage; (iii) a current regulation circuit configured to generate a first control signal in response to the comparison result; and (iv) a driving control circuit configured to limit the input current by the first control signal. | 06-05-2014 |
20140159689 | CONSTANT TIME CONTROL METHOD, CONTROL CIRCUIT AND SWITCH REGULATOR USING THE SAME - In one embodiment, a method of controlling a switching regulator can include: obtaining a voltage feedback signal by detecting an output voltage; generating a triangle wave signal by detecting a current flowing through an inductor; generating a first control signal by superimposing the triangle wave signal and the voltage feedback signal; calculating an error between the voltage feedback signal and a first reference voltage, and compensating for the error to obtain a compensation signal; generating a second control signal by comparing the first control signal against the compensation signal; and controlling switching of a power switch in the switching regulator based on the second control signal and a constant time control signal, where an output signal of the switching regulator is maintained as substantially constant. | 06-12-2014 |
20140169043 | BIAS VOLTAGE GENERATING CIRCUIT AND SWITCHING POWER SUPPLY THEREOF - Disclosed herein are bias voltage generating circuits configured for switching power supplies, and associated control methods. In one embodiment, a bias voltage generating circuit can include: (i) a first control circuit configured to compare a drain-source voltage of a switch against a bias voltage; (ii) a capacitor, with the bias voltage across the capacitor; (iii) a second control circuit configured to control the switch, and that is enabled when the bias voltage is at least as high as an expected bias voltage; (iv) the first control circuit being configured to control the capacitor to charge when the drain-source voltage of the switch is greater than the bias voltage; and (v) the bias voltage being less than an overvoltage protection voltage when the capacitor charges, and where the overvoltage protection voltage comprises a voltage that is a predetermined amount higher than the expected bias voltage. | 06-19-2014 |
20140210353 | HIGH EFFICIENCY LED DRIVING CIRCUIT AND DRIVING METHOD - In one embodiment, an LED driving circuit can include: (i) a sense circuit configured to sense an inductor voltage, and to generate a sense voltage signal; (ii) a protection control circuit configured to activate a first protection control signal in response to a comparison of the sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; (iii) the protection control circuit being configured to activate a second protection control signal in response to a comparison of the sense voltage signal against a second reference voltage to indicate the LED device is in a second load state; and (iv) a PWM control circuit configured to control a power switch according to the first protection control signal or the second protection control signal, based on the load state of the LED device. | 07-31-2014 |
20140210437 | EFFICIENT BOOST-BUCK CONVERTER AND CONTROL METHOD THEREOF - In one embodiment, a boost-buck converter can include: (i) first and second switches coupled in series between input and an output of the boost-buck converter; (ii) a first inductor coupled to the input and third and fourth switches, where the third switch is coupled to ground, and the fourth switch is coupled to the output; (iii) a second inductor coupled to the output and a common node of the first and second switches; and (iv) a control circuit configured to control switching of the first, second, third, and fourth switches according to the input and output voltages, such that the boost-buck converter operates in at least one of: a buck mode and a boost mode. | 07-31-2014 |
20140232190 | MIXED MODE CONTROL FOR SWITCHING REGULATOR WITH FAST TRANSIENT RESPONSES - Methods and circuits for power supply arrangement and control are disclosed herein. In one embodiment, a switching regulator controller can include: (i) a first feedback circuit for sensing an output of a switching regulator to compare against a regulation reference, and to generate a control signal suitable for matching the output of the switching regulator to the regulation reference during a steady state operation of the switching regulator; and (ii) a second feedback circuit for sensing a regulation difference between the output and the regulation reference, and to generate an adjustment signal in response to the regulation difference, where the adjustment signal adjusts the control signal under transient conditions to improve transient responses of said switching regulator. | 08-21-2014 |
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 |
20140246985 | HIGH EFFICIENCY LED DRIVER AND DRIVING METHOD THEREOF - The present invention relates to a high efficiency LED driver, and driving methods thereof. In one embodiment, a high efficiency LED driving method can include: (i) receiving an AC input voltage to obtain an absolute value thereof; (ii) receiving a DC bus voltage, and driving the LED device through a power switch; (iii) generating a first reference voltage according to a driving current and an expected driving current; (iv) comparing the absolute value against a sum of a driving voltage and the first reference voltage; (v) when the absolute value is greater than the sum of the driving voltage and the first reference voltage, turning off the power switch; and (vi) when the absolute value is greater than the driving voltage but less than the sum of the driving voltage and the first reference voltage, turning on the power switch to generate an output current. | 09-04-2014 |
20140300333 | CURRENT DETECTION CIRCUIT AND SWITCH REGULATOR USING THE SAME - In one embodiment, a current detection circuit configured to determine an input current and an output current of a switching regulator, can include: (i) a mirror circuit configured to mirror a current flowing through a main power transistor of the switching regulator to generate a sampling signal that is in proportion to the main power transistor current; (ii) a current generating circuit configured to perform a first average value calculation of the sampling signal based on a switching cycle of the switching regulator to determine the input current; and (iii) the current generating circuit being configured to perform a second average value calculation of the sampling signal based on a conduction duty cycle of the main power transistor to determine the output current. | 10-09-2014 |
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 |
20140361702 | HIGH EFFICIENCY LED DRIVER AND DRIVING METHOD THEREOF - The present invention relates to a high efficiency LED driver and driving method thereof. In one embodiment, a high efficiency LED driving method configured for a LED device can include: (i) receiving a DC bus voltage and generating a driving voltage for the LED device through a power switch; (ii) comparing the DC bus voltage against a sum of the driving voltage and a first reference voltage; (iii) where when the DC bus voltage is greater than the sum of the driving voltage and the first reference voltage, generating a first output current; (iv) where when the DC bus voltage is greater than the driving voltage and less than the sum of the driving voltage and the first reference voltage, generating a second output current; and (v) matching an average current of the first output current and the second output current with a corresponding driving current. | 12-11-2014 |
20150061532 | HIGH EFFICIENCY LED DRIVING CIRCUIT AND DRIVING METHOD - In one embodiment, an LED driving circuit can include: (i) a sense circuit configured to sense an inductor voltage, and to generate a sense voltage signal; (ii) a protection control circuit configured to activate a first protection control signal in response to a comparison of the sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; (iii) the protection control circuit being configured to activate a second protection control signal in response to a comparison of the sense voltage signal against a second reference voltage to indicate the LED device is in a second load state; and (iv) a PWM control circuit configured to control a power switch according to the first protection control signal or the second protection control signal, based on the load state of the LED device. | 03-05-2015 |
20150062987 | LOAD DRIVING CIRCUIT AND METHOD THEREOF - In one embodiment, a method of driving a load can include: monitoring an AC input to a rectifier circuit in real-time, where the rectifier circuit can include first and second rectifier circuits, and controlling first and second controllable switches based on a state of the AC input is in a first state. For example, a first state can include the AC input being in a positive half cycle and increasing, or the AC input being in the positive half cycle and decreasing while being at least as high as a predetermined threshold value. The AC input can be used to supply power to a load circuit and an output capacitor via the first rectifier circuit when the AC input is in the first state, where the first rectifier circuit can include a first diode and the second controllable switch. | 03-05-2015 |