SLUSD37E October 2017 – November 2019 UCC28056
The first step is to produce a small signal model of the PFC Boost converter. A constant power load is assumed to be connected across the output capacitor. This provides the most accurate representation of a switched mode regulator delivering constant output voltage. The plant gain is assumed to be independent of Line voltage due to the action of the internal Line voltage feed-forward circuit. Across the Universal Line voltage range (90 VRMS-264 VRMS), plant gain actually varies by ±-20% due to the quantized nature of the Line voltage feed-forward circuit.