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TYPICAL APPLICATION CIRCUIT

ACT111A

4.8V to 30V Input, 1.5A LED Driver with Dimming Control

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

The ACT111A is a high efficient LED driver

employing current-mode buck converter topology

that supplies up to 1.5A from wide input voltage

range from 4.8V up to 30V. The ACT111A is

designed to operate as a constant source with

1.4MHz fixed frequency. ACT111A consists of a

PWM control circuit, a high precision band-gap

voltage reference, an oscillator, an error amplifier

with internal compensation network and the N

channel power MOSFET. An external sense

resistor in series with the LED monitors output

current allowing accurate current regulation, ideal

for driving high current LEDs. The built-in fault

condition

protection circuits

including

current

limiting, UVLO and thermal shutdown prevent itself

from potentially faulty operation and burn-out.

The ACT111A is ideal for single 1W to 5W LED

drivers. With its ultra low feedback voltage, a low

current ripple, high efficiency of up to 92% step-

down power LED driver can be easily composed of

with additional several external components such

as an inductor, a Schottky diode, a few resistors

and capacitors.

Rev 2, 22-Oct-12