LM3414 datasheet(11/20 Pages) NSC

Part #	LM3414

Description	1A 60W* Common Anode Capable Constant Current Buck LED Driver Requires No External Current Sensing Resistor

PDF	20 Pages

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Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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11 / 20 page

Block Diagram

30124820

Operation Description

OVERVIEW

The LM3414/14HV is a high power floating buck LED driver

with wide input voltage ranges. It requires no external current

sensing elements and loop compensation networks. The in-

tegrated power N-MOSFET enables high output power with

up to 1000 mA output current. The combination of Pulse Width

Modulation (PWM) control architecture and the proprietary

Pulse Level Modulation (PLM) guarantees accurate current

regulation, good EMI performance and provides high flexibil-

ity on inductor selection. High speed dimming control input

allows precision and high resolution brightness control for ap-

plications require fine brightness adjustment.

Application Information

SETTING THE SWITCHING FREQUENCY

Both the LM3414 and LM3414HV are PWM LED drivers that

contain a clock generator to generate constant switching fre-

quency for the device. The switching frequency is determined

by the resistance of an external resistor R

FS in the range of

250 kHz to 1 MHz. Lower resistance of R

FS results in higher

switching frequency. The switching frequency of the

LM3414/14HV is governed by the following equation:

LM3414 Datasheet(PDF) 11 Page - National Semiconductor (TI)