LM3414 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – 1A 60W* Common Anode Capable Constant Current Buck LED Driver Requires No External Current Sensing Resistor

LM3414/LM3414HV
August 9, 2010
1A 60W* Common Anode Capable Constant Current Buck
LED Driver Requires No External Current Sensing Resistor
General Description
The LM3414 and LM3414HV are 1A 60W* common anode
capable constant current buck LED drivers. They are excep-
tionally suitable to drive single string of 3W HBLED with up to
96% efficiency. They accept input voltages from 4.5VDC to
65VDC and deliver up to 1A average LED current with ±3%
accuracy. The integrated low-side N-channel power MOSFET
and current sensing element realize simple and low compo-
nent count circuitry as no bootstrapping capacitor and exter-
nal current sensing resistor are required. An external small-
signal resistor to ground provides very fine LED current
adjustment, analog dimming as well as thermal fold-back
functions.
Constant switching frequency operation eases EMI. No ex-
ternal loop compensation network is needed. The proprietary
Pulse-Level-Modulation (PLM) control method benefits in
high conversion efficiency and true average LED current reg-
ulation. Fast response time realizes fine LED current pulse
fulfilling the 240 Hz 256-step dimming resolution requirement
for general lighting.
The LM3414 and LM3414HV are available in ePSOP-8 and
3mm x 3mm LLP-8 packages.
*Thermal de-rating applies according to actual operation con-
ditions
Features
■ ^{Support LED power up to 60W*: 18x 3W HBLEDs}
■ ^{Requires NO external current sensing resistor}
■ ^{±3% LED current accuracy}
■ ^{Up to 96% efficiency}
■ ^{High contrast ratio (Minimum dimming current pulse width}
<10 µS)
■ ^{Integrated low-side N-channel MOSFET}
■ ^{Adjustable Constant LED current from 350mA to 1000mA}
■ ^{Support analog dimming and thermal fold-back}
■ ^{Wide input voltage range:}
4.5V to 42V (LM3414)
4.5V to 65V (LM3414HV)
■ ^{Constant Switching Frequency adjustable from 250 kHz to}
1000 kHz
■ ^{Thermal shutdown protection}
■ ^{Power enhanced ePSOP-8 or 3mm x 3mm LLP-8 package}
Appications
■ ^{High Power LED Driver}
■ ^{Architectural Lighting, Office Troffer}
■ ^{Automotive Lighting}
■ ^{MR-16 LED Lamp}
Simplified Application Schematic
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