I am looking to create an buck controller for a dimmable LED driver configurable from 3-12 amps with a 3-5V output range and a 9-15V input. This puts me in a bit of an awkward situation since I need super high current (as it is a single diode, high current emitter) but don’t need too high of a voltage. I couldn’t find anything designated as a LED driver specifically for my application so I looked to general purpose controllers, but all of those don’t have PWM dimming functionality or any other way to adjust the constant current output apart from changing the max current limit on some.
Was wondering if anybody knew a part that would fit my needs:
fSW: ~800kHz (can go from 500kHz-2mHz)
type: Synchronous, external MOSFET or internal (if can handle 12 amps max), Constant current buck
duty cycle min: 15%
features: PWM control, max current limit, overtemperature protection, short circuit protection (last 3are prefer to haves but not must)
package size: as long as it isn’t BGA
Another option I saw some discussion about online is a shunt mosfet in parallel with the LED but if I’m not mistaken, isn’t it usually better for the buck controller to be PWM controlled since a shunt MOSFET could cause instability