LM3447MT屬于集成電路（IC）的LED驅(qū)動(dòng)器。由美國(guó)德州儀器公司制造生產(chǎn)的LM3447MTLED 驅(qū)動(dòng)器器件屬于 LED 驅(qū)動(dòng)器電源管理集成電路 (PMIC) 系列，可通過(guò)標(biāo)稱固定電壓的電源為負(fù)載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通常可對(duì)器件工作點(diǎn)進(jìn)行外部控制，可在照明應(yīng)用中用于實(shí)現(xiàn)調(diào)光功能。

1FEATURES

? Integrated Phase Angle Decode

– Leading and Trailing Edge Compatible

– Over 50:1 Dimming Range

? Power Factor Correction with Low Total

Harmonic Distortion

? Primary Side Control Using Input Voltage

Feedforward Technique

? Input Power Regulation Scheme with Improved

Line Regulation

? Constant Power Operation of LEDs to

Compensate for Forward Voltage Variations

Over Temperature and Lifetime

? Fixed Frequency Discontinuous Conduction

Mode Operation

? Valley Switching Operation to Achieve High

Efficiency and Low EMI

? Efficient TRIAC Hold Current Management

? Thermal Foldback Function for LED Protection

? LED Open Circuit and Short Circuit Protection

APPLICATIONS

? Dimmable A19, R20, PAR30/38 LED Lamps

? Recessed LED Downlights and Pendant Lights

? Industrial and Commercial Solid State Lighting

DESCRIPTION

The LM3447 is a versatile power factor correction

(PFC) controller designed to meet the performance

requirements of residential and commercial phase-cut

dimmer compatible LED lamp drivers. The device

incorporates a phase decoder circuit and an

adjustable hold current circuit to provide smooth,

flicker free dimming operation. A proprietary primary

side control technique based on input voltage

feedforward is used to regulate the input power

drawn by the LED driver and to achieve line

regulation over a wide range of input voltage. Valley

switching operation is implemented to minimize

switching loss and reduce EMI. An internal thermal foldback circuit is provided to protects the LEDs from

damage based on the temperature sensed by a

single external NTC resistor. Additional features

include LED open circuit and short circuit protection,

cycle-by-cycle FET over-current protection, burst

mode fault operation using an internal 812ms fault

timer and internal thermal shutdown.

The LM3447 is ideal for implementing dimmable,

isolated single stage LED lamp drivers where

simplicity, low-component count and small solution

size are of primary importance. This device is

currently available in a TSSOP 14-pin package.