Infineon Technologies Austria Ag

Josef Neulinger

Marc Fahlenkamp

Martin Krueger

Torsten Hinz

Jens Barrenscheen

Marcus Schaemann

Techniques are described to adjust the time when a switch is turned on from the time of one voltage valley to the time of another voltage valley for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.

Valley to valley switching in quasi-resonant mode for driver

Techniques for AC input signal detection, whereby a method for AC input signal detection may include: sampling an input signal at a sampling rate, where the input signal is based on an AC signal; comparing the input signal with a threshold signal, determining a first value in case the input signal is larger than the threshold signal; determining at least one second value in case the input signal is smaller than the threshold signal; increasing the sampling rate in case a predefined number of consecutive first values is determined; and decreasing the sampling rate in case the at least one second value is determined.

AC input signal detection

A method of cycle-by-cycle operation of a switched-mode power converter includes converting an input voltage at the primary side to an output voltage at the secondary side by switching a transistor connected to the primary side from an on-state to an off-state during the present cycle, detecting valleys in a voltage across the transistor in the off-state, determining which valley at which the transistor is to be switched from the off-state to the on-state in the next switching cycle, and determining a maximum peak current limit for the primary side above which the transistor is switched from the on-state to the off-state in the next switching cycle. The maximum peak current limit is determined as a function of the input voltage and the valley at which the transistor is to be switched from the off-state to the on-state in the next switching cycle. Forced valley switching techniques are also disclosed.

Peak power limitation and overpower protection for switched-mode power supplies

A method of operating a power supply having a transformer, a transistor controlling the current through a primary side of the transformer, and a control unit for controlling the switching of the transistor to generate current pulses in the transformer, is suggested, the method comprising receiving a feedback signal, and exiting a burst mode and entering a normal mode based on the feedback signal in case the feedback signal exceeds a first threshold value or in case the feedback signal exceeds a second threshold value for at least a first amount of time and in case the feedback signal exceeds a third threshold value, wherein the third threshold value is larger than the second threshold value and the first threshold value is larger than the third threshold value.

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Petershausen, Germany

Josef Neulinger