LT3492

1

3492f

FEATURES

APPLICATIONS

DESCRIPTION

Triple Output LED Driver

with 3000:1 PWM Dimming

The LT

to operate as a constant-current source and is ideal for

driving LEDs. The LT3492 works in buck, boost or buck-

boost mode. The LT3492 uses a fixed frequency, current

mode architecture resulting in stable operation over a

wide range of supply and output voltages. A frequency

adjust pin allows the user to program switching frequency

between 330kHz and 2.1MHz to optimize efficiency and

external component size.

The external PWM input provides 3000:1 LED dimming

on each channel. Each of the three channels has a built-in

gate driver to drive an external LED-disconnect P-channel

MOSFET, allowing high dimming range. The output current

range of each channel of the LT3492 is programmed with

an external sense resistor.

The CTRL pin is used to adjust the LED current either for

analog dimming or overtemperature protection.

Dimming Ratio

60V Internal Switches

Threshold Over a Range of 10mV to 100mV

Operation from 3V to 30V

Transient Protection to 40V

× 5mm) QFN and TSSOP Packages

High Dimming Ratio Triple Output Buck-Mode LED Power Supply

3000:1 PWM Dimming at 100Hz

TYPICAL APPLICATION

0.3A

0.47μF 0.47μF

ISN1

330mΩ

330mΩ

TG1

58V

10 LEDs

33μH

ISP1

0.3A

ISN2

TG2

33μH

ISP2

0.3A

0.47μF

ISN3

1μF

3

330mΩ

10k

150k

49.9k

680pF

3492 TA01a

TG3

33μH

ISP3

SW1

SW2

LT3492

GND

SW3

TG1-3

CTRL1-3

ISP1-3

ISN1-3

PWM1-3

SHDN

3V TO 24V

1μF

FADJ

OVP1-3

1.3MHz

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation.

All other trademarks are the property of their respective owners. Protected by U.S. Patents,

including 7199560, 7321203, and others pending.

PWM

5V/DIV

1μs/DIV

3492 TA01b

0.2A/DIV

0.5A/DIV