Thanks yes, I know and love the LT3799.
But even the LT3799, if used to design an offline flyback led driver, would suffer the problem which I describe….and in fact, I attach two LT3799 simulations which highlight the situation.
I attach on LTspice sim of an LT3799 based, PFC’d flyback led driver of 97W. I also attach a LT3799 based, PFC’d flyback led driver of 20W….you can see that the harmonics are significantly worse for the 20W case.
I actually did a 3rd simulation at 25w…..and that fails mains harmonics (3rd harmonic too high)…whereas the 97W simulation attached…is seen to pass mains harmonics completely.
My original postulation, is that it is not economically feasible to design a PFC’d offline SMPS LED driver of power 235w, that can pass mains harmonics at 235w, and also pass mains harmonics when dimmed down to 25w. Would you agree with this?
I attach the two LTspice sims and the excel of the harmonics.