Abstract: A controller for making a power converter start up normally includes a detection circuit, an upper-bridge power supply pre-charge circuit and a driving signal generation circuit. During the power converter starting up, the detection circuit detects a feedback voltage and adjusts the lower-bridge turning-on time of a lower-bridge switch driving signal of a lower-bridge switch of the power converter according to the feedback voltage. The upper-bridge power supply pre-charge circuit generates the lower-bridge switch driving signal according to the lower-bridge turning-on time and stops generating the lower-bridge switch driving signal when the feedback voltage meets a first predetermined condition.

Abstract: A controler applied to an LLC resonant power converter includes a threshold voltage generation circuit and a gate control signal generation circuit. The threshold voltage generation circuit is used for generating an upper threshold voltage and a lower threshold voltage according to a reference voltage, a feedback voltage, and a gate control signal phase. The gate control signal generation circuit is used for disabling an upper bridge control signal according to a sensing voltage and the upper threshold voltage or disabling an lower bridge control signal according to the sensing voltage and the lower threshold voltage, wherein an upper bridge switch of the LLC resonant power converter is turned on according to the upper bridge control signal, and an lower bridge switch of the LLC resonant power converter is turned on according to the lower bridge control signal.

Abstract: A controller capable of detecting a direct current (DC) voltage information is applied to a power factor correction (PFC) power converter. The controller includes an active switch and a filter. The active switch is used for receiving a detection signal from a detection pin of the controller, and filtering a voltage component of the detection signal to generate a first signal, wherein the voltage component relates to a turning-on period of a power switch of the PFC power converter. The filter is coupled to the active switch and used for filtering a switching component of the first signal to generate the DC voltage information.

Abstract: A combo circuit with electrostatic discharge protection includes a pulse width modulation integrated circuit and a power integrated circuit. The pulse width modulation integrated circuit has an electrostatic discharge protection circuit and the electrostatic discharge protection circuit is installed between a source of the power integrated circuit and a reference ground potential of the combo circuit.

Abstract: A controller applied to a power converter includes a startup and pulse control circuit, a power switch, a startup circuit, and a clamping circuit. The power switch is coupled to a primary side of the power converter and the startup and pulse control circuit, and turned on according to a gate control signal generated by the startup and pulse control circuit. The startup circuit is coupled to the primary side of the power converter, the startup and pulse control circuit and the power switch, and turned on according to a startup signal generated by the startup and pulse control circuit. The clamping circuit is coupled to the startup and pulse control circuit and the power switch, and clamps a current flowing through the startup circuit when the startup circuit is turned on.

Abstract: A primary-side controller applied to a power converter is used for controlling a frequency of a gate control signal according to a grouping mode. The primary-side controller includes a first counter, a second counter, an adjuster, a gate control signal generation circuit, and a logic circuit. The first counter generates a first signal according to the gate control signal and a predetermined number. The second counter generates a second signal according to a clock signal and the predetermined number. The adjuster determines whether to adjust the predetermined number according to the second signal, the predetermined number, and a frequency of the clock signal. The logic circuit generates a reset signal to the first counter and the second counter and an enable signal to the gate control signal generation circuit according to the first signal, the second signal, and the gate control signal.

Abstract: A primary-controller with voltage compensation function applied to a primary side of a power converter includes a gate control signal generation circuit, and the gate control signal generation circuit includes a clamping unit and a driving unit. The gate control signal generation circuit is coupled to a power switch installed in the primary side of the power converter, and is used for enabling a gate control signal, wherein the gate control signal is used for making the power switch turned on. The clamping unit generates a compensation voltage according to a clamping voltage. The driving unit is coupled between the clamping unit and a gate of the power switch, and used for generating the gate control signal according to the compensation voltage. The clamping voltage is changed with a detection voltage of a detection resistor coupled to the power switch accordingly.

Abstract: A controller with variable X-capacitor discharging mechanism includes a voltage detection circuit and a discharging circuit, wherein the controller is applied to a power converter and the X-capacitor is coupled to the power converter. The voltage detection circuit is used for receiving a detection voltage through a pin of the controller and determining whether to generate a discharging signal according to variation of the detection voltage, wherein the detection voltage is generated by an input voltage inputted to the power converter, the input voltage is an alternating current input voltage or a direct current input voltage, and the discharging signal lasts for a predetermined period of time. The discharging circuit is coupled to the voltage detection circuit and the pin, wherein the discharging circuit is used for discharging the X-capacitor according to the discharging signal.

Abstract: A primary controller applied to a primary side of a power converter includes a current peak upper limit adjustment circuit and a gate control signal generation circuit. The current peak upper limit adjustment circuit increases a current peak upper limit of the primary side of the power converter when a gate control signal is enabled at a second valley of a voltage, and reduces the current peak upper limit when the gate control signal is enabled at an Nth valley of the voltage, wherein N is a positive integer. The gate control signal generation circuit is coupled to the current peak upper limit adjustment circuit, wherein the gate control signal generation circuit enables the gate control signal, disables the gate control signal according to the current peak upper limit, and the gate control signal is used for turning on a power switch of the primary side of the power converter.

Abstract: An adjustment circuit is included in a secondary-side controller, wherein the secondary-side controller is installed at a secondary side of an isolated power converter. The adjustment circuit includes a voltage divider, a buffer, a first variable resistor, a second variable resistor, an amplifier, and an N-type metal-oxide-semiconductor transistor. The buffer is coupled to the voltage divider. The first variable resistor is coupled to an external resistor outside the secondary-side controller. The second variable resistor is coupled to the first variable resistor and the buffer. The amplifier is coupled to the first variable resistor and the second variable resistor. The N-type metal-oxide-semiconductor transistor is coupled to a first external capacitor, a bias resistor, and an optocoupler. The first variable resistor and the second variable resistor adjust a characteristic of a Bode plot of the isolated power converter.

Abstract: A secondary-side controller applied to a flyback power converter prevents a secondary side of the flyback power converter from conducting incorrectly. The secondary-side controller includes a first comparison circuit, a second comparison circuit, and a gate control signal generation circuit. The first comparison circuit generates a first comparison signal according to a drain voltage of a synchronous switch of the secondary side of the flyback power converter and a first parameter. The second comparison circuit generates a ready signal according to the first comparison signal and a resistance of an external resistor. The gate control signal generation circuit generates a gate control signal to the synchronous switch according the ready signal and the drain voltage, and the synchronous switch is turned on according to the gate control signal.

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 primary-controller with voltage compensation function applied to a primary side of a power converter includes a gate control signal generation circuit, and the gate control signal generation circuit includes a clamping unit and a driving unit. The gate control signal generation circuit is coupled to a power switch installed in the primary side of the power converter, and is used for enabling a gate control signal, wherein the gate control signal is used for making the power switch turned on. The clamping unit generates a compensation voltage according to a clamping voltage. The driving unit is coupled between the clamping unit and a gate of the power switch, and used for generating the gate control signal according to the compensation voltage. The clamping voltage is changed with a detection voltage of a detection resistor coupled to the power switch accordingly.

Abstract: A controller applied to a power converter is installed in a primary side of the power converter. The controller includes a capacitor, an adjustment signal generation circuit, and a discharge circuit. The capacitor is used for generating a tracking voltage. The adjustment signal generation circuit is used for generating an adjustment signal according to a feedback voltage and the tracking voltage. The discharge circuit is used for discharging the capacitor according to the feedback voltage and the adjustment signal. The tracking voltage is used for tracking a state of a magnetizing current of a magnetizing inductor of the primary side of the power converter, and when the tracking voltage consists with the state of the magnetizing current, the tracking voltage is applied to at least one of zero-voltage switching (ZVS) control and quasi-resonant (QR) control of the power converter.

Abstract: A primary-side controller applied to a power converter is used for controlling a frequency of a gate control signal according to a grouping mode. The primary-side controller includes a first counter, a second counter, an adjuster, a gate control signal generation circuit, and a logic circuit. The first counter generates a first signal according to the gate control signal and a predetermined number. The second counter generates a second signal according to a clock signal and the predetermined number. The adjuster determines whether to adjust the predetermined number according to the second signal, the predetermined number, and a frequency of the clock signal. The logic circuit generates a reset signal to the first counter and the second counter and an enable signal to the gate control signal generation circuit according to the first signal, the second signal, and the gate control signal.

Abstract: A method of switching operational modes of a power converter includes starting up a primary controller applied to the power converter to make the power converter operate in a normal mode; a secondary controller applied to the power converter detecting an output voltage of a secondary side of the power converter and the primary controller detecting an operational frequency of the power converter; if the operational frequency of the power converter is lower than a predetermined frequency and satisfies a first frequency condition, the primary controller controlling the power converter to enter a sleep mode; and when the power converter enters the sleep mode and the output voltage is lower than a trigger voltage, the secondary controller making the primary controller to control the power converter turned on.

Abstract: A primary controller applied to a primary side of a power converter includes a current peak upper limit adjustment circuit and a gate control signal generation circuit. The current peak upper limit adjustment circuit increases a current peak upper limit of the primary side of the power converter when a gate control signal is enabled at a second valley of a voltage, and reduces the current peak upper limit when the gate control signal is enabled at an Nth valley of the voltage, wherein N is a positive integer. The gate control signal generation circuit is coupled to the current peak upper limit adjustment circuit, wherein the gate control signal generation circuit enables the gate control signal, disables the gate control signal according to the current peak upper limit, and the gate control signal is used for turning on a power switch of the primary side of the power converter.

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: An efficiency tracking method of a controller applied to a flyback power converter includes before the controller soft starts, an original frequency variation curve setting voltage generated by the controller outputting an original frequency variation curve setting detection current to an original frequency variation curve setting detection resistor determining a frequency variation curve of the flyback power converter, and utilizing adjustment of resistance of the original frequency variation curve setting detection resistor to achieve efficiency optimization. Therefore, the controller controls an output voltage of the flyback power converter and tracks a maximum power point of the flyback power converter according to the efficiency tracking method to achieve efficiency optimization.

Abstract: A controller applied to a power converter is installed in a primary side of the power converter. The controller includes a capacitor, an adjustment signal generation circuit, and a discharge circuit. The capacitor is used for generating a tracking voltage. The adjustment signal generation circuit is used for generating an adjustment signal according to a feedback voltage and the tracking voltage. The discharge circuit is used for discharging the capacitor according to the feedback voltage and the adjustment signal. The tracking voltage is used for tracking a state of a magnetizing current of a magnetizing inductor of the primary side of the power converter, and when the tracking voltage consists with the state of the magnetizing current, the tracking voltage is applied to at least one of zero-voltage switching (ZVS) control and quasi-resonant (QR) control of the power converter.