Hello All,
I'm working on a multiple output offline flyback converter using UCC28710, for the following specifications :
- Output 1 : 16 V / 50mA
- Output 2 : 16V / 50mA
- Output 3 : 15V / 1A
Using the following transformer spice model :
.subckt FLBTR_VF 6 3 2 1 7 8 9 10 11 12 Llp 6 3x 10u Rp 3x 3xx 540m Lp 3xx 3 450u Ls1 7 8x 15.43u Rs1 8x 8 1 Ls2 9 10x 15.43u Rs2 10x 10 1 Ls3 11 12x 12.5u Rs3 12x 11 0.031 Laux 2 1x 18.66u Raux 1x 1 120m K Lp Ls1 Ls2 Ls3 Laux 0.99 .ends
It appears that the controller does not start-up, as the current through the HV pin is zero.
Please find attached the simulation file. I would appreciate any remarks/advice that you may provide.
Thank you and best regards,