| Patent application number | Description | Published |
|---|
| 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 |
| 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 |
| 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 |
| 20110018590 | FEEDBACK CIRCUIT AND CONTROL METHOD FOR AN ISOLATED POWER CONVERTER - A feedback circuit for an isolated power converter includes an opto-coupler and a reversed polarity regulator. The opto-coupler provides a current related to an output voltage of the isolated power converter. When the isolated power converter enters light load, the output voltage rises and the reversed polarity regulator reduces the current to decrease the power consumption and thus improve the light load efficiency of the isolated power converter. | 01-27-2011 |
| 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 |
