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IRISMPS1

Fig 2)Drain (D) voltage of IRIS4007K (CH1) and the FB pin voltage (CH2) at 36VDC in/Full load output

Fig 2) shows the drain voltage and the feedback pin (FB) voltage. In this case the quasi-resonant signal

swings all the way to near zero volts at the drain before the FET is turned on, and hence underthese

conditions the circuit turns the FET on with near zero voltage switching, due to the quasi-resonant switch-

ing. The FB pin signal shows the current ramp when the FET is on(when the drain voltage is low), and the

resonant signal being passed back during the FET off time.

Fig 3) Drain (D) voltage of IRIS4007K (CH1) and the FB pin voltage (CH2) at 72VDC in/Full load output