LT3496

1

3496fe

FEATURES

APPLICATIONS

DESCRIPTION

Triple Output LED Driver

The LT

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

driving LEDs. The LT3496 works in buck, boost or buck-

boost mode. The LT3496 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 LT3496 supports 3000:1 dimming control on each

channel. Each of the three regulators is independently

operated by that channel’s PWM signal. The PWM feature

allows precise adjustment of the color mixing or dimming

ratio of the LED source. 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 LT3496 is

programmed with an external sense resistor.

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

analog dimming or overtemperature protection.

L, LT, LTC and LTM are registered trademarks 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.

Dimming Ratio

45V 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 LED Power Supply

3000:1 PWM Dimming at 120Hz

TYPICAL APPLICATION

PWM

5V/DIV

0.5μs/DIV

3496 TA01b

0.5A/DIV

0.5A/DIV

0.5A

0.47μF 0.47μF

LED1

200mΩ

200mΩ

TG1

42V

7 LEDs

18μH

CAP1

0.5A

LED2

TG2

18μH

CAP2

0.5A

0.47μF

LED3

1μF

3

200mΩ

470pF

3496 TA01a

TG3

18μH

CAP3

SW1

SW2

LT3496

GND

SW3

TG1-3

VC1-3

CTRL1-3

FADJ

OVP1-3

CAP1-3

LED1-3

PWM1-3

SHDN

PWM1-3

SHDN

3V TO 24V

1μF

22k