Abstract: An apparatus of programming an output of a programmable power adapter according to the present invention comprises a control circuit. The method according to the present invention sends a signal to a device. A resistor is coupled to the signal to determine the level of the signal. The resistor is installed in the device. The method according to the present invention checks the level of the signal in the programmable power adapter and determines an output voltage of the programmable power adapter in accordance with the level of the signal. The output voltage of the programmable power adapter is coupled to the device to provide a power for a load of the device.

Abstract: A control circuit with deep burst mode for power converter according to the present invention comprises a load detection circuit and a PWM circuit. The load detection circuit generates a switching control signal in response to a feedback signal. The feedback signal is correlated to a load condition of the power converter. The PWM circuit generates a switching signal to regulate an output of the power converter in response to the switching control signal and the feedback signal. The control circuit performs a deep burst mode to switch the switching signal only one time during each deep burst period when the load condition of the power converter is a very light-load. Therefore, switching loss is reduced so that the power consumption of the power converter is also reduced.

Abstract: An adaptive sampling circuit of the power converter according to the present invention comprises a sample-and-hold unit and a signal-generation circuit. The sample-and-hold unit is coupled to a transformer to generate a feedback signal by sampling a demagnetized voltage of the transformer in response to a sample signal. The signal-generation circuit generates the sample signal in response to a magnetized voltage of the transformer, the demagnetized voltage of the transformer, a switching signal and a code. The sample signal is used for sampling the demagnetized voltage. The feedback signal is correlated to an output voltage of the power converter. The switching signal is generated in response to the feedback signal for switching the transformer and regulating the output of the power converter. The adaptive sampling circuit is used to precisely measure the demagnetized voltage of the transformer without the limitation of the transformer design.

Abstract: A sampling circuit of the power converter according to the present invention comprises an amplifier circuit receiving a reflected voltage for generating a first signal. A first switch and a first capacitor are utilized to generate a second signal in response to the reflected voltage. A sample-signal circuit generates a sample signal in response to a falling edge of a switching signal. The switching signal is generated in accordance with a feedback signal for regulating an output of the power converter. The feedback signal is generated in accordance with the second signal. The sample signal is utilized to control the first switch for sampling the reflected voltage. The sample signal is disabled once the first signal is lower than the second signal. The sampling circuit precisely samples the reflected voltage of the transformer of the power converter for regulating the output of the power converter.

Abstract: A control circuit of a power converter is provided. It comprises a voltage detection circuit detecting a reflected signal for generating a voltage-loop signal. A current detection circuit detects a current of a transformer for generating a current-loop signal. An oscillator generates an oscillation signal in accordance with an output load of the power converter. A PWM circuit generates a switching signal according to the voltage-loop signal, the current-loop signal and the oscillation signal for regulating an output of the power converter. A load detection circuit receives a detection signal through an signal-transfer device for increasing a switching frequency of the switching signal. The detection signal is generated once the output is lower than a low-voltage threshold. The oscillation signal determines the switching frequency of the switching signal. The control circuit reduces the voltage drop of the output when the output load is changed.

Abstract: A control circuit of a power converter is provided. It comprises a signal generation circuit generating an oscillation signal in accordance with an output load. A PWM circuit generates a switching signal according to a voltage-loop signal, a current-loop signal and the oscillation signal for regulating an output of the power converter. A regulation circuit receives a compensation signal for an output cable compensation and a wake-up. The compensation signal is coupled to increase a switching frequency of the switching signal once the output of the power converter is lower than a low-voltage threshold. The control circuit reduces the voltage drop of the output when the output load is changed.

Abstract: A control circuit of a flyback power converter according to the present invention comprises a low-side transistor, an active-clamper, a high-side drive circuit, and a controller. The low-side transistor is coupled to switch a transformer. The active-clamper is coupled in parallel with the transformer. The high-side drive circuit is coupled to drive the active-clamper. The controller generates a switching signal and an active-clamp signal. The switching signal is coupled to drive the low-side transistor. The switching signal is generated in accordance with a feedback signal for regulating an output of the flyback power converter. The active-clamp signal is coupled to control the high-side drive circuit and the active-clamper. The active-clamp signal is generated in response to a demagnetizing time of the transformer. The pulse number of the active-clamp signal is less than the pulse number of the switching signal in a light load condition.

Abstract: A controller of the power converter according to the present invention comprises a gate driver. The gate driver generates a gate-drive signal. The gate-drive signal is coupled to drive a power transistor to switch a transformer of the power converter for regulating an output of the power converter. The gate driver has a charge-pump circuit for charging pump a voltage level of the gate-drive signal. Therefore, the gate-drive signal can fully turn on the power transistor.

Abstract: Method and apparatus for controlling a programmable power converter are provided. The method and apparatus generate a first power source and a second power source. The voltage level of the second power source is lower than the voltage level of the first power source. The first power source and the second power source provide a power supply for a control circuit. The control circuit will use the first power source as its power supply when the first power source is low. The control circuit will use the second power source as its power supply for saving the power when the first power source is high.

Abstract: A sampling circuit of the power converter according to the present invention comprises an amplifier circuit receiving a reflected voltage for generating a first signal. A first switch and a first capacitor are utilized to generate a second signal in response to the reflected voltage. A sample-signal circuit generates a sample signal in response to the disable of a switching signal. The switching signal is generated in accordance with a feedback signal for regulating an output of the power converter. The feedback signal is generated in accordance with the second signal. The sample signal is utilized to control the first switch for sampling the reflected voltage. The sample signal is disabled once the first signal is lower than the second signal. The sampling circuit precisely samples the reflected voltage of the transformer of the power converter for regulating the output of the power converter.

Abstract: A regulation circuit of a power converter for cable compensation according to the present invention comprises a signal generator generating a compensation signal in accordance with a synchronous rectifying signal. An error amplifier has a reference signal for generating a feedback signal in accordance with an output voltage of the power converter. The compensation signal is coupled to program the reference signal. The feedback signal is coupled to generate a switching signal for regulating an output of the power converter. The regulation circuit of the present invention compensates the output voltage without a shunt resistor to sense the output current of the power converter for reducing power loss.

Abstract: A LED drive circuit according to the present invention comprises a controller and a programmable signal. The controller generates a switching signal coupled to switch a magnetic device for generating an output current to drive a plurality of LEDs. The programmable signal is coupled to regulate a current-control signal of the controller. The switching signal is modulated in response to the current-control signal for regulating the output current, and the level of the output current is correlated to the current-control signal.

Abstract: A method for controlling a power converter is provided. The method includes the following steps. A switching signal coupled to switch a transformer for regulating the output of the power converter is generated in accordance with a feedback signal and a ramp signal. The ramp signal is generated in accordance with a switching current signal and a slope compensation signal. The slope compensation signal is generated in response to an input voltage signal. The input voltage signal is generated in response to the level of the input voltage of the power converter. The feedback signal is generated in accordance with the output of the power converter, and the switching current signal is correlated with a switching current of the transformer.

Abstract: A control circuit of the power converter according to the present invention comprises a feedback circuit, an output circuit and an adaptive clamping circuit. The feedback circuit generates a feedback signal in accordance with an output of the power converter. The output circuit generates a switching signal in accordance with the feedback signal for regulating the output of the power converter. The adaptive clamping circuit limits the level of the feedback signal under a first level for a first load condition. The feedback circuit determines a slew rate of the feedback signal for increasing the level of the feedback signal from the first level to a second level. The adaptive clamping circuit is disabled and the level of the feedback signal can be increased to the second level for a second load condition.

Abstract: An isolation interface circuit is disclosed. The isolation interface circuit comprising a transmitting circuit and a receiving circuit. The transmitting circuit configured to receive a first serial interface signal and a second serial interface signal for generating a differential polarity pulse signal. The receiving circuit configured to receive the differential polarity pulse signal for generating the first serial interface signal and the second serial interface signal. The differential polarity pulse signal are generated in response to the first serial interface signal and the second serial interface signal. The first serial interface signal and the second serial interface signal are generated in accordance with the differential polarity pulse signal. In a period, only one of the transmitting circuit and the receiving circuit can be enabled.

Abstract: A control circuit of a power converter according to the present invention comprises a switching circuit, a sample-and-hold circuit and a current source. The switching circuit generates a switching signal in response to a feedback signal. The sample-and-hold circuit samples the feedback signal. The current source is coupled to a feedback terminal for generating a programming voltage. A programmable signal is generated in accordance with the programming voltage and the feedback signal, and the programmable signal is coupled to set a parameter.

Abstract: A trim circuit for a power supply controller includes: a control circuit; at least a capacitance type programmable circuit connection; and a switching circuit, under control of the control circuit, the switching circuit selectively coupling the capacitance type programmable circuit connection to anyone of an operation voltage and a programming voltage, for determining a programming state of the capacitance type programmable circuit connection.

Abstract: A control circuit of a flyback power converter according to the present invention comprises a low-side transistor, an active-damper, a high-side drive circuit, and a controller. The low-side transistor is coupled to switch a transformer. The active-damper is coupled in parallel with the transformer. The high-side drive circuit is coupled to drive the active-clamper. The controller generates a switching signal and an active-clamp signal. The switching signal is coupled to drive the low-side transistor. The switching signal is generated in accordance with a feedback signal for regulating an output of the flyback power converter. The active-clamp signal is coupled to control the high-side drive circuit and the active-damper. The active-clamp signal is generated in response to a demagnetizing time of the transformer. The pulse number of the active-clamp signal is less than the pulse number of the switching signal in a light load condition.

Abstract: Method and apparatus for controlling a programmable power converter are provided. The method and apparatus generate a first power source and a second power source. The voltage level of the second power source is lower than the voltage level of the first power source. The first power source and the second power source provide a power supply for a control circuit. The control circuit will use the first power source as its power supply when the first power source is low. The control circuit will use the second power source as its power supply for saving the power when the first power source is high.

Abstract: A control circuit with protection circuit for power supply according to the present invention comprises a peak-detection circuit and a protection circuit. The peak-detection circuit detects an AC input voltage and generates a peak-detection signal. The protection circuit comprises an over-voltage protection circuit. The over-voltage protection circuit generates an over-voltage protection signal in response to the peak-detection signal. The protection circuit generates a reset signal to reduce the output of the power supply in response to the over-voltage protection signal. The present invention can protect the power supply in response to the AC input voltage effectively through the peak-detection circuit.