LM3404_07 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – 1.0A Constant Current Buck Regulator for Driving High Power LEDs

June 2007
LM3404/04HV
1.0A Constant Current Buck Regulator for Driving High
Power LEDs
General Description
The LM3404/04HV are monolithic switching regulators de-
signed to deliver constant currents to high power LEDs. Ideal
for automotive, industrial, and general lighting applications,
they contain a high-side N-channel MOSFET switch with a
current limit of 1.5A (typical) for step-down (Buck) regulators.
Hysteretic controlled on-time and an external resistor allow
the converter output voltage to adjust as needed to deliver a
constant current to series and series-parallel connected LED
arrays of varying number and type. LED dimming via pulse
width modulation (PWM), broken/open LED protection, low-
power shutdown and thermal shutdown complete the feature
set.
Features
■ ^{Integrated 1.0A MOSFET}
■ ^V_IN ^{Range 6V to 42V (LM3404)}
■ ^V_IN ^{Range 6V to 75V (LM3404HV)}
■ ^{1.2A Output Current Over Temperature}
■ ^{Cycle-by-Cycle Current Limit}
■ ^{No Control Loop Compensation Required}
■ ^{Separate PWM Dimming and Low Power Shutdown}
■ ^{Supports all-ceramic output capacitors and capacitor-less}
outputs
■ ^{Thermal shutdown protection}
■ ^{SO-8 Package, PSOP-8 Package}
Applications
■ ^{LED Driver}
■ ^{Constant Current Source}
■ ^{Automotive Lighting}
■ ^{General Illumination}
■ ^{Industrial Lighting}
Typical Application
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