I'm designing an LED driver for a set of very high-intensity LEDs, three 3.2A LEDs with a voltage drop of 3.2V, in parallel, powered by a 10.8V or 14.4V array of batteries. So I need an LED driver >90% efficient in a 32mm diameter circular form factor that can push 9.6A at 3.2V. My work is cut out for me. I've designed a buck regulator based on a Texas Instruments TPS53319 controller with built-in switch. Problem is I've never designed a buck current regulator, only voltage regulators, and so I'm not sure how to convert the design.
Mainly I'm not sure how to determine the value of R1 (feedback sense) (in the lower left).
I'm pretty happy with the design if I can get this to work, simulation (for voltage regulation mode) shows efficiency of 94-95% and a 380mm^2 footprint, which should be very doable on the specified PCB size.
Thanks!
Mainly I'm not sure how to determine the value of R1 (feedback sense) (in the lower left).
I'm pretty happy with the design if I can get this to work, simulation (for voltage regulation mode) shows efficiency of 94-95% and a 380mm^2 footprint, which should be very doable on the specified PCB size.
Thanks!