Systems and methods for hysteretically controlling Light Emitting Diodes
(LEDs) when the input voltage is greater than or equal to 18 volts. An
example system includes one or more LEDs and a circuit electrically
coupled to the one or more LEDs. The circuit hysteretically controls an
input voltage supplied to the one or more LEDs based on a sensed electric
current that passes through the LEDs. The circuit includes a MOSFET
switch for switching on and off the input voltage supplied to the one or
more LEDs, a current sensing subcircuit including a first integrated
circuit (IC) for sensing the current flowing through the one or more
LEDs, a hysteretic comparator circuit including a second IC for
generating a hysteretic control signal based on the sensed current, and a
switch driver including a third IC for controlling operation of the
switch based on the generated hysteretic control signal.