Alpha and Omega Semiconductor (cayman) Ltd.

Alpha & Omega Semiconductor Corporation

Chih-Yuan Liu

Pei-Lun Huang

Tien-Chi Lin

Yung-Chuan Hsu

Yu-Ming Chen

Yueh-Ping Yu

Jung-Pei Cheng

Pei-lun Huang

A constant on-time isolated converter comprises 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

A power conversion system and a method for voltage change detection, specifically, relates to a detection circuit implemented in the AC-DC power converter, detect the voltage change. The AC input voltage is rectified to convert into a DC input voltage transmitted to a detection unit generating a detection voltage signal at different logical states corresponding to the input voltage changes. A charge current source unit is used for charging the capacitor when the detection voltage signal is in a second state and a discharge current source unit is used for discharging the capacitor when the detection voltage signal is in a first state. A primary comparator compares the voltage changes of the capacitor in the alternating charge and discharge processes with a critical zero potential and outputs a detection signal identifying the changing trend of the input voltage.

Voltage detection circuit and a method of detecting voltage changes

A constant on-time isolated converter comprising a transformer is disclosed. The transformer primary side connects to an electronic switch and secondary-side connects to a load and a processor. The processor connects 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. The driver receives control signal through the coupling element and accordingly changes the electronic switch ON/OFF state, regulating output voltage and current via the transformer, where the electronic switch ON/OFF duration 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 response to load transient.

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 power conversion systems, specifically, it relates to a device for detecting the DC voltage rectified from the AC power supply voltage in an AC-DC converter, primarily used to determine whether the DC input voltage is under a brown-out level and to monitor whether the AC power supply is removed and to discharge the residue DC voltage generated in a high frequency filter capacitor, which is used to filter high frequency noise signals of the AC power supply, during the removal of the AC power.

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Zhubei, Taiwan

Chih-Yuan Liu