Alpha and Omega Semiconductor (cayman) Ltd.

Alpha and Omega Semiconductor International LP

Alpha & Omega Semiconductor Corporation

Jung-Pei Cheng

Yu-Ming Chen

Pei-Lun Huang

Yueh-Ping Yu

Tien-Chi Lin

Hsiang-Chung Chang

Xiaotian Zhang

Long-Ching Wang

Hung-Ta Hsu

Zhi-Qiang Niu

Yung-Chuan Hsu

Wei-Ting Wang

Chieh-Wen Cheng

Chih-Yuan Liu

Guan-Yu Lin

Bu-Wei Chen

Pao-Yao Yeh

Tsung-Han Ou

Lih-Ming Doong

A flyback converter to control conduction time in AC/DC conversion technology. The flyback converter includes a primary side and a secondary side. The primary side includes a main switch connecting a primary coil to the input of the flyback converter in series. The secondary side includes a secondary coil coupling with the output terminal of the flyback converter. When a switching frequency of the main switch is at a preset first on time in the range between the off frequency and the second switching frequency, the on-time of the main switch continuously changes corresponding to output load changes. When the switching frequency of the main switch is higher than the first switching frequency, the on time of the main switch is constant. The on time is controlled to change linearly, so as to avoid excessive changes in the output voltage ripples, thereby improving circuit efficiency.

Flyback converter for controlling on time variation

An isolated converter has a constant voltage mode and a constant current mode. The isolated converter includes a transformer, a main switch, a driver, a controller, and an isolator. The controller includes a constant current control unit, a voltage comparator, and a control logic unit. The constant current control unit generates a voltage adjustment signal to adjust the reference voltage or voltage feedback signal according to a current feedback signal for sensing the output current. The control logic unit generates a trigger signal according to the comparison signal of the voltage comparator. The isolator connects the output terminal of the controller and the driver. The input terminal is used to transmit the trigger signal to the input terminal of the driver. The isolated converter can provide excellent constant voltage transient response and stable constant current regulation according to load conditions by improving the controller.

Isolated converter with constant voltage mode and constant current mode and control method thereof

A flyback converter, including: a transformer, a first switch, a second switch, and a control circuit. The transformer includes a first side and a second side. The first switch is coupled to the first side at an input terminal. The second switch is coupled to the second side and an output terminal. The control circuit is coupled between the output terminal and the second switch, wherein the control circuit is arranged to adjust a voltage on the input terminal by changing a flow of a current between the second switch and the second side.

Flyback converter and control method thereof

When a constant on-time flyback converter is in the switch-on stage, the gate voltage of the switch and the input voltage of the flyback converter adopt the primary side of the transformer to control. The gate voltage is controlled by the second control signal generated by the controller. The flyback converter is then turn off to enter the switch off stage. When the flyback converter is in the switch off stage, the secondary side controller on the secondary side of the transformer, based on the output voltage and output current of the secondary side, sends a first control signal to the primary side controller to control the main switch to turn on. Thus, the flyback converter enters the switch-on stage. Therefore, the calculation complexity is reduced, and there is no need to set a blanking time, such that the flyback converter can be used in high switching frequency applications.

Constant on-time flyback converter and control method thereof

A charger comprises a housing, a first multi-layer printed circuit board (PCB), a second multi-layer PCB, and a third multi-layer PCB. The first PCB comprises at least a portion of a primary side circuit. The second PCB comprises at least a portion of a secondary side circuit. The third PCB is perpendicular to the first PCB and the second PCB. An isolation coupling element is disposed on the third PCB. The isolation coupling element comprises a multi-layer PCB. The first PCB comprises a high voltage (HV) semiconductor package. A surface of a die paddle of the HV semiconductor package is exposed from a molding encapsulation of the HV semiconductor package.

Super-fast transient response (STR) AC/DC converter for high power density charging application

A multi-port power delivery system includes a first universal serial bus (USB) port, a second USB port, a first power conversion unit, a second power conversion unit, a power delivery control circuit and a switch circuit. The first USB port is configured to output power delivered to a first power path. The second USB port is configured to output power delivered to a second power path. The first power conversion unit has a first output terminal coupled to the first power path. The second power conversion unit has a second output terminal coupled to the second power path. The power delivery control circuit generates a switch control signal according to first connection information on the first USB port and second connection information on the second USB port. The switch circuit selectively couples the first output terminal to the second output terminal according to the switch control signal.

Multi-port power delivery system and related control method

An isolation coupling structure for transmitting a feedback signal between a secondary side and a primary side of a voltage conversion device includes a first dielectric layer including a first face and a second face opposite to the first face, a first coupling coil disposed on the first face enclosing to form an inner region; a second coupling coil configured to couple with the first coupling coil. The second coupling coil includes a first coil portion and a second coil portion, where the first coil portion is disposed on the second face, the second coil portion is disposed on the first face and located inside the inner region. The second coil portion is isolated from the first coupling coil, and the first coil portion and the second coil portion are electrically connected. The technical effect is that it can realize the electrical isolation and the coupling with low cost and small package size.

Isolated coupling structure

A voltage converter comprises a second controller as a power switch of the secondary side of the transformer for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage and generating a control signal, and a coupling element for transmitting the control signal generated by the second controller to the first controller on the primary side of the transformer enabling the first controller to generate a first pulse signal driving the power switch to control the on/off state of the primary side winding.

Pulse transformer

A detection circuit for detecting an inductor current flowing through an inductor is provided. The inductor is coupled to a switch. The detection circuit includes a comparison circuit and a signal generating circuit. The comparison circuit, having a first node, is configured to compare a conduction time of a diode of the switch with a time threshold to provide a first voltage at the first node. The signal generating circuit, coupled to the first node, is configured to output a first detection signal according to the first voltage. The first detection signal indicates whether the inductor current flowing through the inductor reaches a first current threshold. A switching regulator comprises the detection circuit. A control method controls the switching regulator.

Detection circuit, switching regulator having the same and control method

Super-fast transient response (STR) AC/DC Converter for high power density charging application

Voltage converter

The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response.

Growing community of inventors

Zhubei, Taiwan

Jung-Pei Cheng