Power Forest Technology Corporation

Po-Jen Ke

Yang-Tai Tseng

Tso-Min Chen

Yun-Chi Chiang

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.

Power conversion apparatus and charging method thereof

A power conversion apparatus including a synchronous rectification (SR) transistor, a SR controller and a snubber circuit is provided. The SR controller is coupled to the SR transistor to control the SR transistor. A ground terminal of the SR controller is coupled to a source terminal of the SR transistor, and a power terminal of the SR controller is coupled to a system voltage. A first terminal of the snubber circuit is coupled to a drain terminal of the SR transistor. A second terminal of the snubber circuit is coupled to the power terminal of the SR controller. The snubber circuit obtains power from the drain terminal of the SR transistor and provides the system voltage accordingly.

Power conversion apparatus with low power consumption and low cost

A power conversion apparatus and a synchronous rectification (SR) circuit thereof are provided. The power conversion apparatus includes a transformer and the SR circuit. A primary winding of the transformer receives an input voltage. A secondary winding of the transformer provides an output voltage to an output terminal. The SR circuit includes a SR transistor and a SR controller. The SR transistor is coupled between the secondary winding and the output terminal and controlled by a control signal. The SR controller is coupled to the SR transistor to receive a first detecting signal, and generates the control signal according to the first detecting signal. When the SR controller detects that the SR circuit is abnormal, the SR controller generates the controller signal to keep the SR transistor at an on state so as to perform an abnormal protection on the SR circuit.

Power conversion apparatus and synchronous rectification circuit thereof

A power conversion apparatus including a flyback power conversion circuit, a control chip and a detection auxiliary circuit is provided. The flyback power conversion circuit receives and converts an input voltage into a DC output voltage. The control chip generates a PWM signal in response to a power supplying requirement to control the operation of the flyback power conversion circuit, wherein the control chip has a single multi-function detection pin. The detection auxiliary circuit assists the control chip to obtain a first detection voltage via the multi-function detection pin, such that the control chip performs a detection of an over temperature protection (OTP) and a detection of an over voltage protection (OVP) synchronously according to the first detection voltage. The first detection voltage is related to the DC output voltage or a thermal voltage of an environment temperature.

Flyback-based power conversion apparatus

A power conversion apparatus includes a power conversion circuit, a synchronous rectification transistor, a synchronous rectification control circuit, a feedback circuit, and a cable loss compensation circuit. The power conversion circuit converts an input voltage into an output voltage and provides it to a load. The synchronous rectification transistor is coupled in series to a current path on a secondary side of the power conversion circuit and switched according to a synchronous rectification control signal. The synchronous rectification control circuit generates the synchronous rectification control signal for controlling the switching of the synchronous rectification transistor. The feedback circuit generates an output indication current associated with the output voltage. The cable loss compensation circuit draws a compensation current from the feedback circuit according to the synchronous rectification control signal, so as to compensate for the output voltage based on a sum of the compensation current and the output indication current.

Power conversion apparatus

A flyback-based power conversion apparatus and a power conversion method thereof are provided. By switching first and second detection switches disposed in a control chip and coupled to a multi-function pin of the control chip at different timings, the present invention applies a collocation of a voltage-current detection auxiliary circuit and a current detection circuit at a certain timing to execute a detection of the AC input voltage received by a flyback power conversion circuit, and the present invention applies a collocation of the auxiliary voltage-current detection circuit, an over temperature protection unit and an over voltage protection unit at another timing to execute detections of an over temperature protection and an over voltage protection. As the result, a single multi-function detection pin of the control pin is corresponding to a plurality of related function detections, so as to reduce the production cost of manufacturing the control chip.

Flyback-based power conversion apparatus and power conversion method thereof

A driving circuit with an over-voltage protection device for modulating an electrical parameter of a driven device includes at least a boost circuit, a signal processing circuit, an over-voltage protection device, a modulation device and a control circuit. The output terminal of the boost circuit is electrically coupled in series to a driven device, a transistor and a grounded feedback resistor sequentially, wherein the output terminal of the boost circuit is further electrically coupled to a voltage dividing circuit for outputting a voltage dividing signal. The signal processing circuit is provided for outputting a processing signal to the over-voltage protection device and the modulation device according to the voltage dividing signal and a modulation signal. The control circuit is provided for turning on the transistor or not according to an output signal of the over-voltage protection device and an output signal of the modulation device.

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Taoyuan, Taiwan

Po-Jen Ke