LM3402_08 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – 0.5A Constant Current Buck Regulator for Driving High Power LEDs

December 2, 2008
LM3402/LM3402HV
0.5A Constant Current Buck Regulator for Driving High
Power LEDs
General Description
The LM3402/02HV 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 735 mA (typical) for step-down (Buck) regula-
tors. Hysteretic control with controlled on-time coupled with
an external resistor allow the converter output voltage to ad-
just as needed to deliver a constant current to series and
series - parallel connected arrays of LEDs of varying number
and type, LED dimming by pulse width modulation (PWM),
broken/open LED protection, low-power shutdown and ther-
mal shutdown complete the feature set.
Features
■ ^{Integrated 0.5A N-channel MOSFET}
■ ^V_IN ^{Range from 6V to 42V (LM3402)}
■ ^V_IN ^{Range from 6V to 75V (LM3402HV)}
■ ^{500 mA 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}
■ ^{MSOP-8, PSOP-8 Packages}
Applications
■ ^{LED Driver}
■ ^{Constant Current Source}
■ ^{Automotive Lighting}
■ ^{General Illumination}
■ ^{Industrial Lighting}
Typical Application
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