LM3429 Datasheet | National Semiconductor

LM3429 N-Channel Controller for Constant Current LED Drivers .. PRELIMINARY April 30, 2009 N-Channel Controller for Constant Current LED Drivers General Description The LM3429 is a versatile high voltage LED driver controller. With the capability to be configured in a Buck, Boost, Buck Boost (Flyback), or SEPIC topology, and an input and output operating voltage rating of 75V, the LM3429 is ideal for illuminating LEDs in a very diverse, large family of applications. Adjustable high-side current sense with a typical sense voltage of 100 m V allows for tight regulation of the LED current with the highest efficiency possible. Output LED current regulation is based on peak current-mode control with predictive Off-Time Control. This method of control eases the design of loop pensation while providing inherent input voltage feed-forward pensation. The LM3429 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 2.0MHz, thus enabling pact solutions. Additional Features include: precision reference, logic patible DIM input suitable for fast PWM dimming, cycle-by-cycle current limit, and thermal shutdown. The LM3429 es in a low profile, thermally efficient TSSOP EP 14-lead package. Features - - - - - - - - - - - - - VIN range from 4.5V to 75V 2% Internal reference voltage (1.235V) Current sense voltage adjustable from 20 m V High-side current sensing 2Ω MOSFET gate driver Dimming MOSFET gate driver Input under-voltage protection Over-voltage protection Low shutdown current, IQ < 1µA Fast (50k Hz) PWM dimming Cycle-by-cycle current limit Programmable switching frequency TSSOP EP 14-lead package Applications - - - - - - LED Drivers Constant-Current Buck-Boost Regulator Constant-Current Boost Regulator Constant-Current Flyback Regulator Constant-Current SEPIC Regulator Thermo-Electric Cooler (Peltier)...