The LM3433 is an adaptive constant on-time DC/DC buck constant current controller designed to drive a high brightness LED (HB LED) at high forward currents. It is a true current source that provides a constant current with constant ripple current regardless of the LED forward voltage drop. The board can accept an input voltage ranging from -9V to -14V w.r.t. GND. The output configuration allows the anodes of multiple LEDs to be tied directly to the ground referenced chassis for maximum heat sink efficiency when a negative input voltage is used.