Features • VIN range from 4.5V to 75V • Adjustable current sense voltage • High-side current sensing • 2Ω, 1A Peak MosFET gate driver • Input under-voltage protection • Over-voltage protection • PWM dimming • Analog dimming • Cycle-by-cycle current limit • Programmable switching frequency • Thermal Shutdown • TSSOP EP 14-lead package Description The LM3429 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. This flexibility, along with an input voltage rating of 75V, makes the LM3429 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 LM3429 uses Predictive Off-time (PRO) control, which is a combination of peak current-mode control and a predictive off-timer. This method of control eases the design of loop compensation while providing inherent input voltage feed-forward compensation. 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 2.0 MHz, thus enabling compact solutions. Additional features include analog dimming, PWM dimming, over-voltage protection, under-voltage lock-out, cycle-by-cycle current limit, and thermal shutdown. The LM3429 comes in a low profile, thermally efficient TSSOP EP 14-lead package. Applications • LED Drivers • Constant-Current Buck-Boost (or Flyback) Regulator • Constant-Current Boost Regulator • Constant-Current Buck Regulator • Constant-Current SEPIC Regulator • Thermo-Electric Cooler (Peltier) Driver

LM3429   4.50 <= V in Lower  V   <= V in Upper  V   <= 75.00 Ambient Temperature  °C <= 100 What are WEBENCH® tools? Boost Standard Application MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

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Datasheet

Title		Size	Date	Other Language
	LM3429 N-Channel Controller for Constant Current LED Drivers	1048 Kbytes	5-Aug-09

Featured Application Notes

Title		Size	Date	Other Language
	AN-1986: Application Note 1986 LM3429 Boost Evaluation Board	672 Kbytes	3-Aug-09
	AN-1985: Application Note 1985 LM3429 Buck-Boost Evaluation Board	705 Kbytes	3-Aug-09
	AN-1969: Application Note 1969 LM3424 Boost Evaluation Board	988 Kbytes	22-Aug-09
	AN-1967: Application Note 1967 LM3424 Buck-Boost Evaluation Board	1027 Kbytes	22-Aug-09

More Application Notes

Title		Size	Date	Other Language
	AN-1982: Application Note 1982 Small, Wide Input Voltage Range LM2842 Keeps LEDs Cool	63 Kbytes	15-Jul-09

Design Tools

Reference Design

RD-173 - MR16 and PAR38 LED Bulb Reference Design Using National`s LM3429 LED Driver and the Nuventix SynJet® Coolers

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3429MH	ABCD150XV1	0	3868	0	0	2595000	2	736338335
LM3429MHX	ABCD150XV1	0	3868	0	0	2595000	2	736338335

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

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