
LT3003
1
3003fa
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
LED1
8
× 3 = 24 LEDs
350mA PER STRING
VMAX
SHDN
VIN
PWM
LED2
LT3003
LED3
0.1
VEE
GND
OT2
OT1
CAP
10
H
1nF
10
F
0.33
F
LED
VIN
3V TO 16V
VC
3003 TA01a
1
F
1
F
PVIN
32V
GND
SIMPLIFIED LT3476
SW
PWM
DIMMING
TOTAL LED CURRENT (mA)
0
60
EFFICIENCY
(%)
65
70
75
80
90
200
400
600
800
3003 TA01b
1000
1200
85
PVIN = 32V
NUMBER OF LEDS = 8
× 3 = 24
3-Channel LED
Ballaster with PWM
The LT
3003 drives three separate strings of LEDs up
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
TM Dimming Range
■
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
3783
■
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
Efciency