Infineon's ILD4001 are hysteretic buck LED controller ICs for industrial applications realized in a bipolar IC technology. The LED controller is capable to drive external bipolar or MOSFET power transistors.  The IC incorporates a wide input voltage range and the output current level can be adjusted with an external sense resistor. According to the multifunctional control pin the IC can be switched on and off by an external signal, which is also suitable to regulate brightness of the LEDs by PWM dimming. Depending on the value of the switching inductor, the switching frequency and the voltage ripple could be set. The precise internal band-gap stabilizes the circuit and provides stable current conditions over temperature range. Furthermore, over voltage protection and temperature shut down mechanisms enable the IC to protect attached LEDs.

Additional features are included to protect the LEDs from overload, short circuit events, and from over voltage. The LEDs can also be protected against thermal overload by thermally coupling the LEDs to a controller.