LM3424 Datasheet | National Semiconductor

LM3424 Constant Current N-Channel Controller with Thermal Foldback for Driving LEDs .. August 22, 2009 Constant Current N-Channel Controller with Thermal Foldback for Driving LEDs General Description The LM3424 is a versatile high voltage N-channel Mos FET 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 75V, makes the LM3424 ideal for illuminating LEDs in a very diverse, large family of applications. Adjustable high-side current sense voltage 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 pensation 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 4.5V to 75V. 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. Additional Features include slope pensation, softstart, over-voltage and under-voltage lock-out, cycle-by-cycle current limit, and thermal shutdown. Features - - - - - - - - - - - - VIN range from 4.5V to 75V High-side adjustable current sense 2Ω, 1A Peak Mos FET gate driver Input under-voltage and output over-voltage protection PWM and analog dimming Cycle-by-cycle current limit Programmable slope pensation Programmable, synchronizable switching frequency Programmable thermal foldback Programmable softstart Precision voltage reference Low power shutdown and thermal shutdown Applications - - - - - LED Drivers -...