So I used a 3K09 in series with a 5K pot which allows ~400mA to 1A output current. FS is the switching frequency of the driver, higher frequency means a smaller inductor but the minimum output voltage also rises. IE, with 48V in and 500kHz switching frequency (40K Rfs) the minimum output voltage is 9.6V. So you can't run a single LED on a channel. If you raise the frequency to 1MHz the minimum voltage is 19.2V, or 250kHz is 4.8V. You'd have to calculate the inductor value for any given frequency based on how much ripple current you want.
I would suggest sticking with 40K for Rfs and 47uH as shown in their diagram unless you want to optimize for a very specific build.[/QUOTE]
Thanks, 40k and 47uH i had to stick with this so i don't had to order these parts, they are lying around at my parts collection box.