Abstract: A control circuit for controlling a power supply is revealed. The control circuit is used to generate a switching signal for switching the power supply. The control circuit has a detection terminal for detecting a status of the power supply. A first protection circuit is coupled to the detection terminal and to receive a first detection signal via the detection terminal, and the first protection generates a limit signal in response to the first detection signal, for limiting output of the power supply. A second protection circuit is coupled to the detection terminal and to receive a detection signal via thereto, and the second protection generates a protecting signal, for cutting off the output of the power supply, in response to the first detection signal.

Abstract: A method providing short-circuit protection and a flyback converter utilizing the same wire are disclosed. The a method, adopted by a flyback converter, includes a transformer, including generating a feedback voltage according to an output voltage output from a secondary winding of the transformer; controlling a primary current through a primary winding of the transformer based on the feedback voltage; determining a sense voltage according to the primary current; determining a short circuit based on the sense voltage; setting the primary current according to a short-circuit sense voltage limit when a short circuit occurs; and setting the primary current according to a normal sense voltage limit when a short circuit does not occur.

Abstract: Methods for flyback converters are provided. The method, adopted by a flyback converter circuit including a transformer, including: determining an output voltage output from a secondary circuit of the transformer; feeding a feedback voltage based on the output voltage from the secondary circuit back to a primary circuit of the transformer; increasing a current limit and a switching frequency of a primary current with the feedback voltage; and supplying the primary current to a primary winding of the transformer.

Abstract: A power converter is provided. A transformer includes a primary winding for providing a primary voltage according to an input voltage, a secondary winding for providing a secondary voltage according to the primary voltage and an auxiliary winding for providing a reflection voltage according to the secondary voltage. A first switch coupled between the primary winding of the transformer and a ground has a control terminal for receiving a first control signal. A second switch coupled to the secondary winding has a control terminal for receiving a second control signal. A controller provides the first control signal to switch the first switch, so as to control the transformer to provide the secondary voltage. The controller provides the second control signal to switch the second switch according to the first control signal and the reflection voltage, so as to provide an output voltage in response to the secondary voltage.

Abstract: A control circuit for controlling a power supply is revealed. The control circuit is used to generate a switching signal for switching the power supply. The control circuit has a detection terminal for detecting a status of the power supply. A first protection circuit is coupled to the detection terminal and to receive a first detection signal via the detection terminal, and the first protection generates a limit signal in response to the first detection signal, for limiting output of the power supply. A second protection circuit is coupled to the detection terminal and to receive a detection signal via thereto, and the second protection generates a protecting signal, for cutting off the output of the power supply, in response to the first detection signal.

Abstract: A digital dynamic delay modulator and the method thereof are applied to a flyback converter. A first input voltage signal from the flyback converter is received and compared with a threshold voltage to determine whether a counting condition is matched. When the counting condition is matched, an integer predetermined count number is counted to determine a delay time. After finishing the counting, a first output signal is generated to turn on a switching device for the flyback converter. The slope of the first input voltage signal is detected when the switching device is turned on, and the slope is used to adjust the count number with integer increment/decrement. Therefore, the delay time for switching the flyback converter can be precisely controlled in digital and dynamic manner.

Abstract: A startup control circuit with an acceleration startup function and a method for operating the same are disclosed. The startup control circuit is applied to a power supply. A power switch, which is coupled to a primary-side winding of a transformer, is switched to control the transformer, thus adjusting the output voltage of the power supply. The startup control circuit mainly includes a capacitor and a startup control apparatus. The startup control apparatus includes an enable switch unit and a power control unit. By turning on and turning off the enable switch unit of the startup control apparatus, the acceleration startup control and the stable output power of the power supply can be implemented.

Abstract: A digital dynamic delay modulator and the method thereof are applied to a flyback converter. A first input voltage signal from the flyback converter is received and compared with a threshold voltage to determine whether a counting condition is matched. When the counting condition is matched, an integer predetermined count number is counted to determine a delay time. After finishing the counting, a first output signal is generated to turn on a switching device for the flyback converter. The slope of the first input voltage signal is detected when the switching device is turned on, and the slope is used to adjust the count number with integer increment/decrement. Therefore, the delay time for switching the flyback converter can be precisely controlled in digital and dynamic manner.