Leadtrend Technology Corporation

Meng-Jen Tsai

Ming-Chang Tsou

Chih-Chi Chang

Da-Chun Wei

Chao-Chih Lin

Yu-Kun Lin

Ming-Yen Lin

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.

Primary-controller with voltage compensation function and operational method thereof

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.

Controller applied to a power converter and operational method thereof

A protection circuit applied to an alternating current (AC) power source includes a sample-and-hold unit, a detection unit, and a discharge signal generation unit. The sample-and-hold unit samples a peak value of a direct current (DC) voltage during each period of a corresponding AC voltage, wherein the AC power source provides the AC voltage. The detection unit generates a detection signal when the DC voltage crosses a reference voltage corresponding to the peak value. The discharge signal generation unit generates a count signal when the discharge signal generation unit does not receive the detection signal within a predetermined time of a period of the AC voltage, accumulates the count signal, and generates a discharge signal to a discharge unit when a number of accumulated count signals is greater than a predetermined value, wherein the discharge unit discharges an X capacitor according to the discharge signal.

Protection circuit applied to an alternating current power source and related protection method thereof

A controller of a power converter includes a sample-and-hold unit and an adjustment unit, wherein the power converter is applied to a Universal Serial Bus power delivery adapter system. The sample-and-hold unit is used for sampling a voltage to generate a sampling voltage during each period of a gate control signal, wherein the sampling voltage corresponds to an output voltage of the power converter. The adjustment unit is coupled to the sample-and-hold unit for adjusting at least one of a frequency of the gate control signal, a current flowing through a primary side of the power converter, and a resistance of a compensation resistor of the controller according to the sampling voltage.

Controller of a power converter and operation method thereof

A control circuit applied to a power converter includes a multi-functional pin, a zero-crossing signal generator, and an over-voltage detector. The multi-functional pin is used for receiving an auxiliary current generated by an auxiliary winding of the power converter, and an input current. The zero-crossing signal generator is used for generating a zero-crossing signal according to the auxiliary current. The over-voltage detector is used for generating an over-voltage signal according to the auxiliary current. The control circuit generates a switch control signal to the power switch according to the zero-crossing signal, or generates an over-voltage protection signal to the power switch according to the over-voltage signal.

Control circuit applied to a power converter and operation method thereof

An oscillator applied to a control circuit of a power converter includes a compensation module and an oscillation module. The compensation module outputs or sinks an adjustment current according to a compensation voltage corresponding to a load, a direct current voltage of a primary side of the power converter, and a reference voltage. The oscillation module outputs a clock signal according to the compensation voltage, a control voltage, and the adjustment current. The control circuit generates a gate control signal to a power switch of the primary side according to the clock signal. When the compensation voltage is less than a first predetermined voltage, a frequency of the gate control signal is a first fixed value, and when the compensation voltage is between the first predetermined voltage and a second predetermined voltage and greater than the second predetermined voltage, the frequency is varied with the compensation voltage.

Oscillator applied to a control circuit of a power converter and control method thereof

A controller for eliminating acoustic noise of a power converter includes a control unit and a gate signal generation unit. The control unit is used for detecting a frequency corresponding to a gate control signal in a burst mode of the power converter. When the frequency is greater than a predetermined frequency, the control unit increases a resistance of a compensation resistor coupled to a compensation pin of the power converter; and when the frequency is less than the predetermined frequency, the control unit decreases the resistance of the compensation resistor. The gate signal generation unit is coupled to the control unit for generating the gate control signal to a power switch of a primary side of the power converter according to the resistance of the compensation resistor. The power switch is turned on according to the gate control signal.

Controller for eliminating acoustic noise of a power converter and related method thereof

A device for detecting an average output current of a power converter includes a current generation unit, a first voltage generation unit, a first current mirror unit, and a second current mirror unit. The current generation unit generates a first charge current according to an intermediate voltage. The first voltage generation unit generates a first node voltage according to the first charge current, a first discharge current, a turning-on time, and an inverse turning-on time. The first current mirror unit generates a first current according to the first node voltage, and generates a second voltage corresponding to the average output current of a secondary side of the power converter according to the first current. The second current mirror unit generates the first discharge current according to the first current.

Device and method for detecting an average output current of a power converter

A controller for controlling a power converter to output constant power includes a current sensing module, a voltage generation module, and a voltage regulation module. The current sensing module generates a sensing current according to an output current flowing through a secondary side of the power converter. The voltage generation module generates a set voltage corresponding to a reciprocal of the sensing current according to the sensing current. The voltage regulation module generates a regulation voltage to a feedback circuit of the secondary side of the power converter according to the set voltage and a sensing voltage corresponding to an output voltage of the secondary side of the power converter. The feedback circuit and a primary side of the power converter regulate the output voltage according to the regulation voltage, where a product of the output voltage and the output current is a constant value.

Controller for controlling a power converter to output constant power and related method thereof

An active feedback control integrated circuit applied to an alternating current/direct current converter includes a feedback pin, an operation unit, a control unit, and a controlled-current generation unit. The feedback pin is used for receiving a feedback current of an output feedback unit of the alternating current/direct current converter. The operation unit is used for generating an operation signal according to the feedback current. The control unit is coupled to the operation unit for generating a current control signal. The controlled-current generation unit is coupled to the control unit for generating a controlled current to the feedback pin according to the current control signal.

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Hsin-Chu, Taiwan

Meng-Jen Tsai