Infineon Technologies Austria Ag

Infineon Technologies Ag

Guoxing Zhang

Mingping Mao

Weifu Yu

Nitin Agarwal

Junyang Luo

Tong Bao

In accordance with an embodiment, a method of operating a power supply includes detecting a loss of at least one of an AC input voltage an AC input power at an input of the power supply, and increasing a switching frequency of the power supply upon detection of the loss of the AC input voltage or AC input power.

System and method for detecting a loss of AC power in a switched-mode power supply

According to an embodiment, a circuit comprising includes a first switching circuit coupled to a power supply input, a second switching circuit coupled to an output of the first switching circuit, a supply capacitor coupled to the second switching circuit, and a startup cell coupled to the power supply input and the supply capacitor. The startup cell is configured to electrically couple the power supply input to the supply capacitor when the second switching circuit is not actively switching. The startup cell is also configured to electrically decouple the power supply input from the supply capacitor when the second switching circuit is actively switching.

System and method for a startup cell circuit

In accordance with an embodiment, a method of controlling a switched-mode power includes generating a feedback signal proportional to an output of the switched-mode power supply, and operating the switched-mode power supply in a normal mode. If the feedback signal crosses a first threshold, the switched-mode power operates in a second operating mode. In the first operating mode the pulse modulated signal is adjusted to regulate a feedback signal to a first signal level, and in the second operating mode, a dead-time of the pulse modulated signal is adjusted to signal to regulate a feedback signal to a second signal level different from the first signal level. The method further includes driving a switch of the switched-mode power supply with the pulse modulated signal.

Multi-mode operation and control of a resonant converter

A device for current protection comprises a switch-mode power supply controller. The switch-mode power supply controller includes an inrush current comparator that is arranged to compare a primary winding current with an inrush current threshold at least during at least one of a startup phase or a burst phase. The switch-mode power supply controller also includes a switch controller that is arranged to control regulation of an output voltage by controlling turning of a primary switch on and off based on a feedback signal that is based, at least in part, on the output voltage. The switch controller is further arranged to, if the inrush current comparator determines that the primary winding current has reached the inrush current threshold, control the primary switch to turn off and remain turned off until at least a next switching cycle.

Switch-mode power supply current monitoring with over current and overload protection

A method and apparatus for controlling a flyback converter are presented. The flyback converter includes a transformer, a semiconductor switch coupled to a primary winding of the transformer, a current measurement circuit coupled to the semiconductor switch, a diode coupled in series to a secondary winding of the transformer, and a controller. The controller is configured to receive a feedback voltage, a reference signal, and the measured primary current and generate a control signal for the semiconductor switch dependent on the feedback voltage, the reference signal, and the measured primary current. The semiconductor switch switches on and off cyclically in CCM operation.

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Singapore, Singapore

Guoxing Zhang