PFS7329H Drain Oscillations

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I have oscillations on Drain of PFC controller. Is this normal behavior?

Voltage on D of PFS7329H72.37 KB

The waveform you show is perfectly normal behavior - it's a classic discontinuous ring waveform that occurs when the PFC inductor discharges completely into the load during the primary switch off-time. Residual energy in the inductor that is not sufficient to turn on the output diode sloshes around in the primary circuit, making a decaying sinusoidal waveform with a frequency determined by the inductor value and the stray capacitance.This is absolutely nothing to worry about, and happens with other SMPS topologies as well as the boost converter.