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LM3401_08 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – Hysteretic PFET Controller for High Power LED Drive | |||
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March 13, 2008
LM3401
Hysteretic PFET Controller for High Power LED Drive
General Description
The LM3401 is a switching controller designed to provide
constant current to high power LEDs. The LM3401 drives an
external P-MOSFET switch for step-down (Buck) regulators.
The LM3401 delivers constant current within ±6% accuracy
to a wide variety and number of series connected LEDs. Out-
put current is adjusted with an external current sensing resis-
tor to drive high power LEDs in excess of 1A.
For improved accuracy and efficiency, the LM3401 features
dual-side hysteresis, very low reference voltage, and short
propagation delay. A cycle by cycle current limit provides pro-
tection against over current and short circuit failures. Addi-
tional features include adjustable hysteresis and a CMOS
compatible input pin for PWM dimming.
Features
â Hysteretic Control for Speed and Simplicity
â Input Operating Range of 4.5V-35V
â 1.5MHz maximum switching frequency
â Low 200mV reference voltage
â Programmable current limit
â High speed CMOS compatible enable/dimming
â Adjustable hysteresis
â Input UVLO
â No output capacitor required
â MSOP-8 package
Applications
â LED Driver
â Battery Charger
Typical Application Circuit
© 2008 National Semiconductor Corporation 300214
30021401
www.national.com
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