LM3402 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – 0.5A Constant Current Buck Regulator for Driving High Power LEDs

October 2006
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) regu-
lators. Hysteretic control with controlled on-time coupled with
an external resistor allow the converter output voltage to
adjust 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
n Integrated 0.5A N-channel MOSFET
n V_IN Range from 6V to 42V (LM3402)
n V_IN Range from 6V to 75V (LM3402HV)
n 500 mA Output Current Over Temperature
n Cycle-by-Cycle Current Limit
n No Control Loop Compensation Required
n Separate PWM Dimming and Low Power Shutdown
n Supports all-ceramic output capacitors and
capacitor-less outputs
n Thermal shutdown protection
n MSOP-8 Package
Applications
n LED Driver
n Constant Current Source
n Automotive Lighting
n General Illumination
n Industrial Lighting
Typical Application
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