TPS92314A - 22 LED in series - Isolated solution

Since the tool is for an isolated design the TPS92314 doesn't know what the output voltage is except through the turns ratio. I would use the calculator set up for an LED string of 9 leds with 4 volts Vf and 600 mA of current, change the output rectifier Vf to half of what you're using. This sets the power level the same as what you are doing and Vout is 1/2 what you want, 36 volts. When you're figured out with the calculator what you desire just use half the turns ratio to the secondary for your design (double the turns on the secondary) which would double the voltage and half the current, 72 volts, 300 mA. From the primary side they look the same. You'll have to check things on the calculator related to the secondary side to make sure you scale it right, such as Lsecondary will be 4X what the calculator states because it changes by n^2.

Thanks a lot. Will try and let you know if it works !!