LT3003

1

3003fa

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

LED1

8

× 3 = 24 LEDs

350mA PER STRING

SHDN

PWM

LED2

LT3003

LED3

0.1

Ω

GND

OT2

OT1

CAP

10

µH

1nF

10

µF

0.33

µF

LED

3V TO 16V

3003 TA01a

1

µF

1

µF

32V

GND

SIMPLIFIED LT3476

SW

PWM

PWM

DIMMING

TOTAL LED CURRENT (mA)

0

60

65

70

75

80

90

200

400

600

800

3003 TA01b

1000

1200

85

NUMBER OF LEDS = 8

× 3 = 24

3-Channel LED

Ballaster with PWM

The LT

to 350mA/channel with 3% accurate current matching,

resulting in uniform LED brightness and intensity. This

approach is superior to conventional methods of running

three separate channels with external ballast resistors

requiring expensive factory calibration.

The LT3003 operates in boost, buck and buck-boost mode.

A True Color PWM Dimming ratio of up to 3000:1 is achiev-

able using a logic-level signal at the PWM pin for all modes

without the need for external level-shifting circuitry. For

applications with input supply above and below the output

voltage of the LED strings, the LT3003 allows the LEDs to

be returned to the input supply (buck-boost mode) instead

of being limited to only SEPIC solutions.

The LT3003 is ideal for high power LED driver applications

such as TFT LCD backlighting and heads-up displays. Ad-

ditional overtemperature outputs allow appropriate system

management for increased reliability.

The LT3003 is available in a small 10-pin MSE package.

■

High Power LED Ballaster

■

Automotive Lighting

■

Video Cameras

■

TFT LCD Backlighting

■

3% LED Current Matching

■

Up to 350mA Continuous Current per LED String

■

Up to 3000:1 True Color PWM

■

PWM Input Disconnects LED Strings

■

Can Operate in Buck, Boost and Buck-Boost Modes

■

Wide Input Range: 3V to 40V

■

Overtemperature Outputs

■

Works with LT1618, LT3477, LT3474, LT3475,

LT3476, LTC

■

Thermally Enhanced 10-Pin MSOP Package

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

True Color PWM is a trademark of Linear Technolology Corporation.

All other trademarks are the property of their respective owners.

Buck Mode LT3003 with the LT3476

Efficiency