Abstract: A secondary-side control method of a flyback power converter includes a primary controller included in the flyback power converter generating a first gate control signal to turn on a power switch at a first predetermined valley of a first voltage after the primary controller enters a start-up mode; and a secondary controller included in the flyback power converter generating a trigger pulse to a synchronous switch at a second predetermined valley of a second voltage to make the primary controller enter a secondary-side control mode from the start-up mode after the secondary controller detects a first coupling voltage corresponding to the first gate control signal on the second voltage.

Abstract: A secondary controller applied to a secondary side of a power converter includes a control signal generation circuit and a gate control signal generation circuit. The gate control signal generation circuit generates a gate control signal, and generates an injection signal according to the gate control signal. When a superposition voltage is less than a reference voltage, the control signal generation circuit generates a gate pulse control signal, wherein the gate pulse control signal corresponds to an output voltage of the power converter and the injection signal, the gate control signal generation circuit is further used for generating a gate pulse signal according to the gate pulse control signal, and the gate pulse signal is used for making a primary side of the power converter turned on.

Abstract: A power supply has multiple DC power sources converted from an AC power source. The power supply has an isolated converter converting the AC power source into an intermediate DC power source, and non-isolated converters converting the intermediate DC power source into the DC power sources, regulated at target output values respectively. A communication channel connects the isolated converter and one of the non-isolated converters, and transmits a feedback signal in association with the target output values. The isolated converter, in response to the feedback signal, regulates the intermediate DC power source at an intermediate target value related to the target output values.

Abstract: A power supply has a transformer, a rectifier switch, a secondary-side controller and two diodes. The transformer includes a primary winding, a secondary winding, and a detection winding, inductively coupling to one another. The rectifier switch is connected in series with the secondary winding between two output power lines. The secondary-side controller is electrically coupled to two ends of the detection winding, for controlling the rectifier switch in response to two terminal signals at the two ends respectively. The two diodes are back-to-back electrically connected in series between the two ends, and a joint connecting the two diodes is electrically connected to one of the two output power lines.

Abstract: A secondary controller applied to a secondary side of a power converter includes a control signal generation circuit. The control signal generation circuit is coupled to an output terminal of the secondary side of the power converter for detecting an output voltage of the secondary side and enabling a pulse signal to a signal source of the secondary side of the power converter, wherein the signal source enables a turning-on signal according to the pulse signal. The turning-on signal is coupled to a primary-side auxiliary winding of the power converter through a secondary-side auxiliary winding of the power converter to make the primary-side auxiliary winding generate a voltage, and a primary controller of a primary side of the power converter makes the primary side of the power converter be turned on according to the voltage.

Abstract: A secondary controller applied to a secondary side of a power converter includes a control signal generation circuit. The control signal generation circuit is coupled to an output terminal of the secondary side of the power converter for detecting an output voltage of the secondary side and enabling a pulse signal to a signal source of the secondary side of the power converter, wherein the signal source enables a turning-on signal according to the pulse signal. The turning-on signal is coupled to a primary-side auxiliary winding of the power converter through a secondary-side auxiliary winding of the power converter to make the primary-side auxiliary winding generate a voltage, and a primary controller of a primary side of the power converter makes the primary side of the power converter be turned on according to the voltage.

Abstract: A power supply has a transformer, a rectifier switch, a secondary-side controller and two diodes. The transformer includes a primary winding, a secondary winding, and a detection winding, inductively coupling to one another. The rectifier switch is connected in series with the secondary winding between two output power lines. The secondary-side controller is electrically coupled to two ends of the detection winding, for controlling the rectifier switch in response to two terminal signals at the two ends respectively. The two diodes are back-to-back electrically connected in series between the two ends, and a joint connecting the two diodes is electrically connected to one of the two output power lines.

Abstract: A secondary controller applied to a secondary side of a power converter includes a control signal generation circuit, a voltage detection signal generation circuit, and a gate control signal generation circuit. The control signal generation circuit generates a short-circuited control signal to a short winding switch after a gate control signal to make the short winding switch be turned on. When an output voltage of the power converter is less than a predetermined voltage, the voltage detection signal generation circuit generates a first detection signal to the control signal generation circuit. The control signal generation circuit further generates a gate pulse control signal according to the first detection signal. The gate control signal generation circuit generates a gate pulse signal according to the gate pulse control signal, wherein the gate pulse signal is used for making a primary side of the power converter be turned on.

Abstract: A ripple suppressor includes a constant current generation circuit and a voltage regulation circuit. The constant current generation circuit is coupled to a light-emitting diode chain, wherein the constant current generation circuit is used for generating a detection voltage, and generating a constant current to the light-emitting diode chain. The voltage regulation circuit is coupled to the light-emitting diode chain and the voltage regulation circuit, wherein the voltage regulation circuit makes the constant current generation circuit generate the constant current according to the detection voltage and a compensation value, or makes the constant current generation circuit generate the constant current according to the detection voltage, wherein the compensation value is changed with an average voltage generated by the voltage regulation circuit, and the average voltage corresponds to a voltage of an end of the light-emitting diode chain.

Abstract: A ripple suppressor includes a constant current generation circuit and a voltage regulation circuit. The constant current generation circuit is coupled to a light-emitting diode chain, wherein the constant current generation circuit is used for generating a detection voltage, and generating a constant current to the light-emitting diode chain. The voltage regulation circuit is coupled to the light-emitting diode chain and the voltage regulation circuit, wherein the voltage regulation circuit makes the constant current generation circuit generate the constant current according to the detection voltage and a compensation value, or makes the constant current generation circuit generate the constant current according to the detection voltage, wherein the compensation value is changed with an average voltage generated by the voltage regulation circuit, and the average voltage corresponds to a voltage of an end of the light-emitting diode chain.

Abstract: A secondary controller applied to a secondary side of a power converter includes a control signal generation circuit, a voltage detection signal generation circuit, and a gate control signal generation circuit. The control signal generation circuit generates a short-circuited control signal to a short winding switch after a gate control signal to make the short winding switch be turned on. When an output voltage of the power converter is less than a predetermined voltage, the voltage detection signal generation circuit generates a first detection signal to the control signal generation circuit. The control signal generation circuit further generates a gate pulse control signal according to the first detection signal. The gate control signal generation circuit generates a gate pulse signal according to the gate pulse control signal, wherein the gate pulse signal is used for making a primary side of the power converter be turned on.

Abstract: A dimming controller is capable of receiving a dimming signal to dim light-emitting device no matter the dimming signal is of a first type or of a second type. A type identifier identifies whether the dimming signal received from an input node is of the first type or of the second type, to accordingly generate a selection signal. A signal converter generates a first signal in response to the dimming signal, and the first signal is of the first type. A multiplexer has two inputs receiving the first signal and the dimming signal respectively, and, in response to the selection signal, forwards one of the first signal and the dimming signal to a driver driving the light-emitting device.

Abstract: A dimming controller is capable of receiving a dimming signal to dim light-emitting device no matter the dimming signal is of a first type or of a second type. A type identifier identifies whether the dimming signal received from an input node is of the first type or of the second type, to accordingly generate a selection signal. A signal converter generates a first signal in response to the dimming signal, and the first signal is of the first type. A multiplexer has two inputs receiving the first signal and the dimming signal respectively, and, in response to the selection signal, forwards one of the first signal and the dimming signal to a driver driving the light-emitting device.

Abstract: A secondary controller applied to a secondary side of a power converter includes a detector and a standby signal generation circuit. The detector is used for detecting a first signal and a second signal of a universal serial bus device, and a frequency of a synchronization signal corresponding to a primary side of the power converter. The standby signal generation circuit is coupled to the detector for delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal.

Abstract: A secondary controller applied to a secondary side of a power converter includes a detector and a standby signal generation circuit. The detector is used for detecting a first signal and a second signal of a universal serial bus device, and a frequency of a synchronization signal corresponding to a primary side of the power converter. The standby signal generation circuit is coupled to the detector for delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal.

Abstract: An exemplary light-emitting diode (LED) driving circuit includes a LED driving IC, at least a LED string and at least a resistor. The LED string each is electrically coupled between a power source voltage and a control terminal of the LED driving IC and whereby a driving current of the LED string is subjected to the control of the LED driving IC. The resistor each is electrically coupled to between the control terminal and a predetermined potential. Moreover, a LED driving method also is provided.

Abstract: A circuit with adjustable phase delay and a feedback voltage includes a delay setting unit and a phase delay signal generator. The delay setting unit generates a delay time according to an external resistor. The phase delay signal generator includes a plurality of phase delay units. Each phase delay unit includes an edge trigger subunit and a signal generation subunit. The edge trigger subunit receives an input signal, and generates a positive edge trigger signal and a negative edge trigger signal according to a positive edge and a negative edge of the input signal, respectively. The signal generation subunit generates and outputs a phase delay signal according to the positive edge trigger signal, the negative edge trigger signal, and the delay time. The phase delay signal lags the input signal for the delay time.

Abstract: Short protection control circuits and related control methods are disclosed. A disclosed short protection control circuit is adapted for controlling a short protection mechanism providing short protection to several LED chains. The disclosed short protection control circuit has a detection circuit, a first logic circuit and a timer. Coupled to the LED chains, the detection circuit asserts an indication signal when one of the node voltages of the LED chains is lower than an under-current reference. When the indication signal is enabled, the first logic circuit starts blocking the short protection mechanism. The timer times to provide a result when the short protection mechanism is blocked. When the result indicates that the short protection mechanism has been blocked for at least a predetermined time period, the first logic circuit resumes the short protection mechanism.

Abstract: A control circuit of light emitting diodes is used for driving at least one series of light emitting diodes. The control circuit includes a current setting pin, a driving current generator, a regulator circuit, and an adjuster. A reference current flows through the current setting pin. The driving current generator is used for generating a driving current flowing through the series of light emitting diodes according to the reference current. The adjuster generates an adjustment voltage according to the reference current. Then, the regulator circuit generates a supply voltage to drive the series of light emitting diodes, and regulates a voltage of a first terminal of the series of light emitting diodes at a target voltage according to the adjustment voltage. The target voltage is increased with decrease of the driving current when the driving current is less than a first predetermined current.

Abstract: A circuit with adjustable phase delay and a feedback voltage includes a delay setting unit and a phase delay signal generator. The delay setting unit generates a delay time according to an external resistor. The phase delay signal generator includes a plurality of phase delay units. Each phase delay unit includes an edge trigger subunit and a signal generation subunit. The edge trigger subunit receives an input signal, and generates a positive edge trigger signal and a negative edge trigger signal according to a positive edge and a negative edge of the input signal, respectively. The signal generation subunit generates and outputs a phase delay signal according to the positive edge trigger signal, the negative edge trigger signal, and the delay time. The phase delay signal lags the input signal for the delay time.