Alpha and Omega Semiconductor (cayman) Ltd.

Alpha and Omega Semiconductor International LP

Alpha & Omega Semiconductor Corporation

Yueh-Ping Yu

Tien-Chi Lin

Jung-Pei Cheng

Yu-Ming Chen

Pei-Lun Huang

Hsiang-Chung Chang

Xiaotian Zhang

Long-Ching Wang

Zhi-Qiang Niu

Chih-Yuan Liu

Yung-Chuan Hsu

Hung-Ta Hsu

Guan-Yu Lin

Wei-Ting Wang

Tin-Wei Chen

Bu-Wei Chen

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 signal transmission circuit is configured for transmitting control information from a secondary side of a power converter to a primary side of the power converter. The signal transmission circuit includes a transmitter circuit, a signal transformer and a detection circuit. The transmitter circuit is configured to generate a ramp signal at least according to a first control signal outputted from the secondary side. The first control signal indicates the control information provided for a switch in the primary side. The signal transformer, coupled to the transmitter circuit, is configured to convert the ramp signal to generate an output signal. The output signal includes a positive-going component and a negative-going component to indicate the control information. The detection circuit, coupled to the signal transformer, is configured to detect the positive-going component and the negative-going component to provide the control information for the switch.

Signal transmission circuit for providing control information from secondary side to primary side of power converter, and control circuit for power converter

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 flyback converter includes a transformer, a sensing impedance, a switch and a control circuit. The sensing impedance is coupled between the transformer and an output terminal of the flyback converter. The switch is coupled to the transformer. The transformer is charged when the switch activates. The transformer is discharged when the switch deactivates. The control circuit is arranged to detect if the sensing impedance is bypassed, and further arranged to adjust an operating frequency of the switch when the sensing impedance is bypassed.

Flyback converter, control circuit thereof, and associated control method

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 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

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.

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.

Constant on time COT control in isolated converter

The present invention relates to a power supply device for voltage converter, which includes a master switch, a first controller for generating a first pulse signal to drive the master switch to be turned on and turned off, a second controller for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage to determine the logic state of a control signal generated by the second controller, and a coupling element connected between the first controller and the second controller for transmitting the logic state of the control signal to the first controller and enabling the first controller to determine the logic state of the first pulse signal according to the logic state of the control signal. The second controller includes a driving module for generating a second control signal to drive a synchronous switch to be turned on and turned off.

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Zhubei, Taiwan

Yueh-Ping Yu