Abstract: A detection circuit for a power supply circuit is provided. The detection circuit includes a reference circuit, a voltage detection circuit, and a determination circuit. The reference circuit is coupled to a thermal circuit of the power supply circuit through a connection pin. The voltage detection circuit stops the reference circuit from providing a temperature reference signal, and samples a single-phase AC input power through the connection pin. When a peak value information of the single-phase AC input power is sampled, the voltage detection circuit stores the peak value information and enables the reference circuit to provide the temperature reference signal. The determination circuit provides at least one of a waveform detection signal and an over-voltage detection signal in response to the peak value information, and provides an over-temperature detection signal according to at least one of an output signal of the thermal circuit and the peak value information.

Abstract: A power supply device is provided. The power supply device includes a power converter and a controller. The controller controls the power converter to generate an output power. The controller includes a first detection circuit and a second detection circuit. The first detection circuit detects the output power to obtain a first detection result. The first detection result is a variation of an output current value of the output power. The second detection circuit detects electrical characteristics other than the output current value to obtain a second detection result. The controller determines whether to limit output of the output power according to a relationship between the first detection result and the second detection result.

Abstract: An asymmetric half-bridge converter is provided. The asymmetric half-bridge converter includes a switch circuit, a resonance tank, a current sensor, and a controller. The current sensor senses a waveform of a resonance current flowing through the resonance tank to generate a sensing result. The controller determines the sensing result. When the sensing result indicates that an ending current value of a primary resonance waveform of the resonance current is greater than a predetermined value, the controller performs a first switching operation on the switch circuit. When the sensing result indicates that the ending current value of the primary resonance waveform is less than or equal to the predetermined value, the controller performs a second switching operation on the switch circuit.

Abstract: A power conversion device and a control circuit are provided. The power conversion device includes a power conversion circuit and a control circuit. The control circuit includes a first controller and a second controller. The power conversion circuit includes an input capacitor, a rectifier circuit, and a power switch. The input capacitor is coupled to an input terminal of the power conversion device. The rectifier circuit converts an input AC power into a rectified power. The first controller operates the power switch to cause the power conversion circuit to convert the rectified power into an output power. The second controller detects a signal waveform at the input terminal, and controls the first controller in response to the signal waveform at the input terminal, so as to utilize the power switch to discharge the charge stored in the input capacitor.

Abstract: A power supply apparatus and an impedance adjustment method thereof are provided. An adjustment control circuit controls an impedance adjustment circuit to adjust an equivalent impedance of a feedback circuit according to variation of an output voltage of a power supply circuit, to adjust a feedback voltage in response to the variation of the output voltage.

Abstract: A power conversion apparatus and a synchronous rectification controller thereof are provided. At least one of a differentiation operation and an integration operation is performed on a drain voltage signal of a synchronous rectification transistor. According to at least one of a differential signal obtained by performing the differential operation and an integral signal obtained by performing the integral operation, it is determined whether to turn on the synchronous rectification transistor at the next time when the drain voltage signal is less than or equal to a turn-on threshold voltage.

Abstract: An asymmetric half-bridge converter is provided. The asymmetric half-bridge converter includes a switch circuit, a resonance tank, a current sensor, and a controller. The current sensor senses a waveform of a resonance current flowing through the resonance tank to generate a sensing result. The controller determines the sensing result. When the sensing result indicates that an ending current value of a primary resonance waveform of the resonance current is greater than a predetermined value, the controller performs a first switching operation on the switch circuit. When the sensing result indicates that the ending current value of the primary resonance waveform is less than or equal to the predetermined value, the controller performs a second switching operation on the switch circuit.

Abstract: A power supply device is provided. The power supply device includes a power converter and a controller. The controller controls the power converter to generate an output power. The controller includes a first detection circuit and a second detection circuit. The first detection circuit detects the output power to obtain a first detection result. The first detection result is a variation of an output current value of the output power. The second detection circuit detects electrical characteristics other than the output current value to obtain a second detection result. The controller determines whether to limit output of the output power according to a relationship between the first detection result and the second detection result.

Abstract: A power conversion apparatus and a synchronous rectification controller thereof are provided. At least one of a differentiation operation and an integration operation is performed on a drain voltage signal of a synchronous rectification transistor. According to at least one of a differential signal obtained by performing the differential operation and an integral signal obtained by performing the integral operation, it is determined whether to turn on the synchronous rectification transistor at the next time when the drain voltage signal is less than or equal to a turn-on threshold voltage.

Abstract: An LLC converter circuit is provided. A control circuit provides a first control signal and a second control signal according to a sensing voltage generated by sensing a voltage on a resonant capacitor of a primary side, so as to control a conduction state of a half-bridge switch circuit.

Abstract: A power conversion apparatus and a synchronous rectification (SR) controller thereof are provided. An open-loop control circuit outputs a clamp voltage as a driving voltage when a drain voltage of a synchronous rectification transistor rises to a second voltage, so as to quickly pull down the driving voltage and maintain the driving voltage at a clamp voltage. Therefore, a second control circuit may quickly turn off the synchronous rectification transistor when the drain voltage is greater than a third voltage.

Abstract: A power conversion apparatus and a synchronous rectification (SR) controller thereof are provided. An open-loop control circuit outputs a clamp voltage as a driving voltage when a drain voltage of a synchronous rectification transistor rises to a second voltage, so as to quickly pull down the driving voltage and maintain the driving voltage at a clamp voltage. Therefore, a second control circuit may quickly turn off the synchronous rectification transistor when the drain voltage is greater than a third voltage.

Abstract: A power supply apparatus and a discharge method thereof are provided. A control unit detects a cross-voltage across two ends of an AC safety capacitor to generate a detection voltage, compares the detection voltage with a threshold voltage, counts the number of cycles of the detection voltage during a period when the detection voltage does not cross the threshold voltage according to a comparison result between the detection voltage and the threshold voltage, and performs a discharge operation when the number of cycles is greater than or equal to a predetermined value to discharge electric energy stored in the AC safety capacitor.

Abstract: A power conversion apparatus and a charging method of the power conversion apparatus are provided. A synchronous rectifier controller provides a voltage of a drain terminal of a synchronous rectifier transistor to charge a capacitor of a power supply terminal of the synchronous rectifier controller when the synchronous rectifier transistor is turned from an on state to an off state and a voltage of the power supply terminal is less than a preset voltage.

Abstract: A voltage conversion apparatus and a voltage conversion method thereof are provided. A conversion circuit converts outputs of a plurality of secondary windings to generate a conversion voltage or a conversion current to a resistor network of a feedback circuit to thereby change impedance characteristics of the resistor network. The feedback circuit adjusts a feedback voltage in response to the change in the impedance characteristics of the resistor network, so that a control circuit controls an output of a transformer circuit according to the feedback voltage.

Abstract: A power conversion apparatus and a charging method of the power conversion apparatus are provided. A synchronous rectifier controller provides a voltage of a drain terminal of a synchronous rectifier transistor to charge a capacitor of a power supply terminal of the synchronous rectifier controller when the synchronous rectifier transistor is turned from an on state to an off state and a voltage of the power supply terminal is less than a preset voltage.

Abstract: A voltage conversion apparatus for implementing zero-voltage switching based on recovering leakage inductance energy is provided. A leakage inductance energy recovery circuit is coupled to a primary side auxiliary winding and a control circuit, and recovers leakage inductance energy of a transformer circuit to supply an operating power to the control circuit. Before a main switch is turned on the next time, leakage inductance energy recovered previously is used to lower a cross-voltage of the main switch, so that transient loss of conduction of the main switch is eliminated or reduced, and circuit efficiency is improved.

Abstract: A voltage conversion apparatus and a voltage conversion method thereof are provided. A conversion circuit converts outputs of a plurality of secondary windings to generate a conversion voltage or a conversion current to a resistor network of a feedback circuit to thereby change impedance characteristics of the resistor network. The feedback circuit adjusts a feedback voltage in response to the change in the impedance characteristics of the resistor network, so that a control circuit controls an output of a transformer circuit according to the feedback voltage.

Abstract: An LED backlight system and an LED control circuit are provided. The LED backlight system includes an LED string and the LED control circuit. The LED control circuit includes an LED driver, a switching circuit and an abnormality detecting circuit. The LED driver is configured to generate a control signal. The switching circuit controls a current flowing through the LED string in response to the control signal. The abnormality detecting circuit is configured to detect a voltage or the current of a first end of the LED string. When the voltage or the current of the first end of the LED string is less than or equal to a threshold value, the abnormality detecting circuit turns off the switching circuit, and the abnormality detecting circuit detects an impedance of the first end of the LED string to determine an abnormal state of the LED string.

Abstract: A pulse width modulation control circuit and a control method of a pulse width modulation signal are provided. A counter circuit generates a count value according to a phase-locked loop clock, and resets the count value according to a transition point of a synchronization signal. A comparison circuit compares the count value with a duty ratio set value, and sets the pulse width modulation signal to a high level while the count value is less than the duty ratio set value.