Patent application number | Description | Published |
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 |
20080298095 | Light-load efficiency improving method and apparatus for a flyback converter - A flyback converter has a controller to switch a power switch so as to convert an input voltage to an output voltage for a load by monitoring an output voltage dependent signal and a current sensing signal derived from a current flowing through the power switch, a light-load efficiency improving apparatus monitors the load and a supply voltage provided for the controller to selectively clamp the output voltage dependent signal when the load is lower than a first threshold value and the supply voltage is lower than a second threshold value, so as to increase the supply voltage. | 12-04-2008 |
20090116160 | Arrangement and method for an integrated protection for a power system - For protecting a power system, two or three of over current, thermal and under voltage protection circuits are integrated as one protection circuit but operate independently, and one or more protection points thereof are adjusted dynamically in response to detected condition of the power system. Specifically, using voltage and current conditions in the power system to modify the over current protection and the thermal protection maximizes the performance of the power system and covers the process bias in the circuits. | 05-07-2009 |
20100117617 | Negative lock loop and control method for a flyback voltage converter - A flyback voltage converter includes a transformer having a primary winding and a secondary winding, a switch serially connected to the primary winding for being switched to produce a current in the secondary winding, and a negative lock loop to adjust the peak value of the current in the secondary winding according to a current conduction time during which the current in the secondary winding is higher than a current threshold, such that the peak value of the current in the secondary winding will be in inverse proportion to the time. | 05-13-2010 |
Patent application number | Description | Published |
20080224782 | Frequency jittering control circuit and method for using the same - A frequency jittering control circuit wherein by means of the characteristics of a PLL whose input switches between different frequencies, the output frequency of the PLL swings between the different frequencies to achieve the desired frequency jittering. | 09-18-2008 |
20080284503 | Charge Pump Start up Circuit and Method Thereof - The present invention discloses a charge pump start up circuit comprising: a start up transistor having one end which is electrically connected with a voltage supply source, and another end which is electrically connected to a voltage node; and a charge pump circuit having an input which is electrically connected with the voltage node, and an output which is electrically with the gate of the start up transistor. | 11-20-2008 |
20080298605 | Half-Voltage Headphone Driver Circuit - The present invention discloses a half-voltage headphone driver circuit, comprising: at least one operational amplifier providing an output to a headphone speaker, and a charge pump receiving a supply voltage (VDD), generating a positive half-voltage and a negative half-voltage (VDD/2 and −VDD/2) based on the supply voltage, and supplying the positive half-voltage and negative half-voltage as high and low operation levels to the at least one operational amplifier. | 12-04-2008 |
20090115391 | Load-Dependent Frequency Jittering Circuit and Load-Dependent Frequency Jittering Method - The present invention discloses a load-dependent frequency jittering circuit, comprising: a load condition detection circuit for receiving a switching signal and generating an output according to a load condition; a number generator for receiving the output of the load condition detection circuit and generating a number; a digital to analog converter for converting the output of the number generator to an analog signal; and an oscillator for generating a jittered frequency according to the output of the digital to analog converter. | 05-07-2009 |
Patent application number | Description | Published |
20120146515 | DRIVING DEVICE FOR LED MODULE - A driving device for a LED module is provided. The driving device for the LED module includes a voltage converting unit, a LED module voltage detecting unit, and a switching signal generation unit. The voltage converting unit produces a driving voltage to drive the LED module according to a switching signal. The LED module voltage detecting unit divides the driving voltage to produce a comparison voltage. The switching signal generation unit receives the comparison voltage by a fault detection pin and compares a reference voltage and the comparison voltage to enable or disable the switching signal. After the switching signal is disabled, the switching signal generation unit further pulls up a voltage level of the fault detection pin to a logic high level voltage, so as to produce a fault notification signal to let the fault detection pin also have a function for fault notification. | 06-14-2012 |
20140029310 | POWER CONVERSION APPARATUS - A power conversion apparatus is disclosed. The power conversion apparatus includes a power transistor, a thermal resistor and a temperature detection circuit. A control terminal of the power transistor receives a control signal. The power transistor converts an input voltage into an output voltage according to the control signal. The thermal resistor has a negative temperature coefficient. The temperature detection circuit generates the control signal and provides a driving current to the control terminal of the power transistor according to the control signal. The temperature detection circuit further generates an over temperature protection signal according to the driving current. | 01-30-2014 |
20140063856 | VOLATGE CONVERTING APPARATUS AND SUB-HARMONIC DETECTOR THEREOF - A voltage converting apparatus and a sub-harmonic detector are disclosed. The sub-harmonic detector includes a pulse eliminating circuit, a counter, and a comparator. The pulse eliminating circuit receives a pulse width modulation (PWM) signal and a reference PWM signal having a same period. The PWM signal and reference PWM signal has a plurality of pulses and reference pulses respectively. The pulse eliminating circuit eliminates at least one part of the pulses which overlap with the reference pulses for generating a processed signal. The counter counts the processed signal and the PWM signal during a time period to obtain first and second counting values. The comparator compares the first and second counting values for detecting whether a sub-harmonic condition happens or not in the PWM signal. | 03-06-2014 |
20140071718 | FLY-BACK POWER CONVERTING APPARATUS - A structure of a fly-back power converting apparatus is disclosed. The structure includes a power transistor, a current detector, a pulse width modulation (PWM) signal generator and a current limiter. The power transistor is coupled to an input voltage and receives a PWM signal. The current detector detects a current output from the power transistor and generates a detecting voltage according to the current. The PWM signal generator generates the PWM signal according to a comparing result by comparing the detecting voltage and a standard voltage. The current limiter generates the standard voltage according to a turn-on time of the power transistor. | 03-13-2014 |
20140097822 | POWER SUPPLY AND STARTUP CIRCUIT THEREOF - A power supply and its startup circuit are provided. The startup circuit includes a first transistor, a bias resistor, a pull-down switch, a voltage detector, and a discharging path generator. A first end of the first transistor receives alternating current (AC) input power. The bias resistor is serially coupled between a second end and a control end of the first transistor. The pull-down switch is turned on or turned off according to a detection result. The voltage detector generates the detection result by detecting a voltage on the second end of the first transistor. The discharging path generator provides a discharging path between the second end of the first transistor and a reference ground voltage according to the detection result. | 04-10-2014 |
20140159684 | BUCK POWER CONVERTER - A buck power converter includes a power transistor, an inductor, a first diode, and an anti-ringing circuit. The power transistor has a first terminal, a second terminal, and a control terminal. The first terminal of the power transistor receives an input voltage, and the control terminal of the power transistor receives a pulse width modulation (PWM) signal. The anti-ringing circuit detects a detection voltage on the second terminal of the power transistor. According to the detection voltage, the anti-ringing circuit provides at least one second diode serially coupled between the second terminal of the power transistor and a reference ground terminal in a forward-biased manner, so as to clamp a voltage swing of the detection voltage. | 06-12-2014 |
20140176104 | BUCK VOLATGE CONVERTING APPARATUS - A buck voltage converting apparatus is disclosed. The buck voltage converting apparatus includes a first transistor, a second transistor, an inductor, a controller and a switch. The first transistor receives an input voltage. A first terminal of the inductor is coupled to the first and second transistors. A second terminal of the inductor is coupled to an output terminal of the buck voltage converting apparatus for generating an output voltage. The controller receives the output voltage, and generates a detection voltage according to voltage amplitude of the output voltage. The switch is coupled between a first terminal of the first transistor and a control terminal of the second transistor. The switch is turned on or off according to the detection voltage. | 06-26-2014 |
20140218162 | ELECTRIC FIELD RESISTOR - An electric field resistor includes N coils. N coils encircle a common center in sequence, and each of the coils has a first terminal and a second terminal, wherein the first terminal of the first coil receives a first reference voltage, the second terminal of the N | 08-07-2014 |
20140253060 | VOLTAGE CONVERTER - A voltage converter includes a constant on time signal generator, a first transistor, a second transistor, an inductor, and a ripple injection circuit. The constant on time signal generator generates a first driving signal and a second driving signal. The ripple injection circuit receives an output signal and generates a ripple injection signal. The constant on time signal generator generates the first and second driving signals according to the ripple injection signal, the output signal, and a reference signal. | 09-11-2014 |