LM3429_0908 Datasheet, PDF (1/34 Pages) National Semiconductor (TI) – N-Channel Controller for Constant Current LED Drivers

LM3429
August 3, 2009
N-Channel Controller for Constant Current LED Drivers
General 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 pos-
sible. 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 frequen-
cies 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-cy-
cle current limit, and thermal shutdown.
The LM3429 comes in a low profile, thermally efficient TSSOP
EP 14-lead package.
Features
■ ^V_IN ^{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}
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}
Typical Application Circuit
Boost LED Driver
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