Patent ID: 7705547

Claim:
A Light Emitting Diode (LED) system comprising: one or more LEDs; and a circuit electrically coupled to the one or more LEDs for hysteretically controlling an input voltage supplied to the one or more LEDs, wherein the circuit is configured to operate with all input voltages within a range of approximately 5 volts to approximately 76 volts, wherein the circuit comprises: a switch for switching on and off the input voltage supplied to the one or more LEDs; a current sensing subcircuit for sensing the current flowing through the one or more LEDs; a hysteretic comparator subcircuit for generating a hysteretic control signal based on the sensed current; and a switch driver for controlling operation of the switch based on the generated hysteretic control signal, and wherein the current sensing subcircuit senses current on a high side of the one or more LEDs.