Constant current N-channel controller with Thermal Foldback for driving LEDs

The LM3424 is a versatile high voltage N-channel MOSFET controller for LED drivers. It can be easily configured in buck, boost, buck-boost and SEPIC topologies. In addition, the LM3424 includes a thermal foldback feature for temperature management of the LEDs. This flexibility, along with an input voltage rating of 75 V, makes the LM3424 ideal for illuminating LEDs in a large family of applications.

Adjustable high-side current sense allows for tight regulation of the LED current with the highest efficiency possible. The LM3424 uses standard peak current-mode control providing inherent input voltage feed-forward compensation for better noise immunity. It is designed to provide accurate thermal foldback with a programmable foldback breakpoint and slope. In addition, a 2.45V reference is provided.

The LM3424 includes a high-voltage startup regulator that operates over a wide input range of 4.5 V to 75 V. The internal PWM controller is designed for adjustable switching frequencies of up to 2.0 MHz and external synchronization is possible. The controller is capable of high speed PWM dimming and analog dimming.