| Patent application number | Description | Published |
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| 20100225249 | LED Driver with Direct AC-DC Conversion and Control, and Method and Integrated Circuit Therefor - The present invention discloses an LED driver with direct AC-DC conversion and control function, and a method and integrated circuit therefor. The LED driver comprises: a primary side circuit receiving rectified AC power, the primary side circuit including at least one power switch; a transformer coupled to the primary side circuit and controlled by the at least one power switch to convert a primary voltage to a secondary voltage which is supplied to an LED circuit; and a secondary side circuit coupled to the transformer, the secondary side circuit directly controlling current flowing through the LED circuit and sending a feedback signal to the primary side circuit to control the at least one power switch thereby. | 09-09-2010 |
| 20100301760 | Light Emitting Device Driver Circuit, Light Emitting Device Array Controller and Control Method Thereof - The present invention discloses a light emitting device array controller which controls a power stage to supply an output voltage to one end of each of a plurality of light emitting device strings. The other end of each of the light emitting device strings is coupled to a corresponding transistor having a current inflow end, a current outflow end and a control end. The present invention obtains signals from the control ends of the transistors instead of the current inflow ends, and feedback controls the output voltage according to the highest voltage of the control ends. Thus, the number of pins required for a circuit chip is reduced. | 12-02-2010 |
| 20100301761 | Tail-less LED Control Circuit - The present invention discloses a tail-less LED control circuit, which includes: a power supply stage having an output terminal which provides electrical power to an LED circuit; an output capacitor coupled to the output terminal; an LED driver circuit coupled to the power supply stage for controlling the power supply stage to provide the electrical power to the LED circuit, the LED driver circuit receiving a PWM dimming signal for adjusting brightness of the LED circuit; and a MOSFET switch coupled to the output capacitor in series, the MOSFET switch switching synchronously with the PWM dimming signal to alleviate LED afterglow, wherein the MOSFET switch includes a body diode having an anode-cathode direction against the discharge direction of the output capacitor. | 12-02-2010 |
| 20100301764 | LED Controller with Phase-Shift Dimming Function and LED Phase-Shift Dimming Circuit and Method Thereof - The present invention discloses an LED controller with phase-shift dimming function and an LED Phase-Shift dimming circuit and method thereof. The LED controller includes: a power circuit for supplying DC power to multiple LED channels; and an LED phase-shift dimming circuit for receiving a pulse width modulation (PWM) input signal and generating multiple phase-shifted PWM signals with a shifted phase between one another, wherein a turn-ON timing of each of the multiple phase-shifted PWM signals follows a turn-OFF timing of a previous PWM signal which is the input PWM signal or a previous one of the multiple phase-shifted PWM signals. | 12-02-2010 |
| 20100308749 | AC Power Line Controlled Light Emitting Device Dimming Circuit and Method Thereof - The present invention discloses an AC power line controlled light emitting device dimming circuit and a method thereof. The AC power line controlled light emitting device dimming circuit includes: a light emitting device driver circuit for controlling current through a light emitting device, wherein the light emitting device is current-controlled; and a level adjustment circuit for detecting power-OFF of an AC power switch and generating a corresponding level adjustment signal which is transmitted to the light emitting device driver circuit to control the current through the light emitting device accordingly. | 12-09-2010 |
| 20110012537 | Driver circuit and method for driving load circuit - The present invention discloses a driver circuit and a method for driving a load circuit. The driver circuit includes: a primary side circuit receiving rectified AC power; a transformer coupled to the primary side circuit and converting a primary voltage to a secondary voltage which is supplied to a load circuit; and a secondary side circuit coupled to the transformer, the secondary side circuit detecting current flowing through the load circuit and feedback controlling the primary side circuit accordingly. | 01-20-2011 |
| 20110057637 | BOUNDARY CONDUCTION MODE SWITCHING REGULATOR AND DRIVER CIRCUIT AND CONTROL METHOD THEREOF - The present invention discloses a boundary conduction mode (BCM) switching regulator, and a driver circuit and a control method of the switching regulator, for controlling a power stage to convert an input voltage to an output voltage or output current. The BCM switching regulator detects whether it is operating in continuous conduction mode (CCM) or discontinuous conduction mode (DCM), and adjusts the On-time, Off-time, or frequency of the power stage accordingly, so that the switching regulator operates in or near BCM. | 03-10-2011 |
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| 20090102431 | Universal serial bus charger circuit and charging method - The present invention discloses a universal serial bus (USB) charging circuit, comprising: a charging path for charging a battery from a USB host; a charging switch located on the charging path; a current sensing circuit for sensing current information on the charging path; a maximum available current detection circuit for detecting the maximum available current from the USB host; and a loop controller circuit for controlling the charging switch so that the charging current on the charging path is substantially equal to the maximum available current detected by the maximum available current detection circuit, wherein the maximum available current detection circuit detects the maximum available current during circuit initialization and stores it. | 04-23-2009 |
| 20100164282 | Multi-output Switching regulator and control method therefor - The present invention discloses a multi-output switching regulator, comprising: a single-input-multiple-output voltage converter converting an input voltage to a first output voltage at a first node and a second output voltage at a second node; an input capacitor connected with the input voltage at an input node; a first output capacitor having two ends, one of which is connected with the first node; and a second output capacitor having two ends, one of which is connected with the second node; wherein the other end of the first output capacitor is connected to ground, the input node or the second node, and the other end of the second output capacitor is connected to ground, the input node or the first node. | 07-01-2010 |
| 20110012570 | Synchronous driver circuit and integrated circuit for use therein - The present invention discloses a synchronous driver circuit, comprising: an inductor having one end coupled to an input voltage; a first power transistor having one end coupled to the other end of the inductor and another end supplying an output voltage; a second power transistor having one end coupled to the other end of the inductor and another end coupled to ground; a control circuit for controlling the operation of the first and second power transistors; a gate driver coupled to the control circuit and having an output controlling the gate of the first power transistor; and a bootstrap capacitor having one end coupled to a voltage node and the other end coupled to the other end of the inductor, the voltage across the bootstrap capacitor being provided as the operational voltage of the gate driver. | 01-20-2011 |
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| 20090195221 | Capacitor charger with a modulated current varying with an input voltage and method thereof - In a capacitor charger including a transformer having a primary winding connected with an input voltage and a secondary winding for transforming a primary current flowing through the primary winding to a secondary current flowing through the secondary winding, the primary current is adjusted according to a monitoring voltage varying with the input voltage, thereby prolonging the lifetime of the battery that provides the input voltage and improving the power efficiency of the battery. | 08-06-2009 |
| 20090201078 | Single-chip common-drain JFET device and its applications - A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation. | 08-13-2009 |
| 20090201079 | Single-chip common-drain JFET device and its applications - A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation. | 08-13-2009 |
| 20090206921 | Single-chip common-drain JFET device and its applications - A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation. | 08-20-2009 |
| 20090206922 | Single-chip common-drain JFET device and its applications - A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation. | 08-20-2009 |
| 20090237062 | Single-chip common-drain JFET device and its applications - A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation. | 09-24-2009 |
