Datasheet LT3519, LT3519-1, LT3519-2 (Analog Devices)

LT3519/LT3519-1/LT3519-2 LED Driver with Integrated Schottky Diode
FEATURES DESCRIPTION
n
Up to 3000:1 True Color PWM™ Dimming
The LT®3519/LT3519-1/LT3519-2 are fi xed frequency n
Wide Input Voltage Range
step-up DC/DC converters designed to drive LEDs. They
Operation from 3V to 30V
feature an internal 45V, 750mA low side switch and Schottky
Transient Protection to 40V
diode. Combining a traditional voltage feedback and a n
Rail-to-Rail LED Current Sense from 0V to 45V
unique rail-to-rail current sense feedback allows these n
45V, 750mA Internal Switch
converters to operate as a constant-voltage source or n
Internal Schottky Diode
constant-current source. Internal compensation simplifi es n Constant-Current and Constant-Voltage Regulation applications. These devices feature rail-to-rail LED current n Boost, SEPIC, Buck-Boost Mode or Buck Mode sense pins that provide the most fl exibility in choosing a Topology converter confi guration to drive the LEDs. The LED cur- n Open LED Protection and Open LED Status Pin rent is externally programmable with a sense resistor. The n Programmable Undervoltage Lockout with Hysteresis external PWM provides up to 3000:1 PWM dimming and n Fixed Frequency: 400kHz (LT3519), 1MHz (LT3519-1), the CTRL input provides analog dimming. 2.2MHz (LT3519-2) 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. n Internal Compensation All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560 and 7321203. n CTRL Pin Provides Analog Dimming n Low Shutdown Current: <1μA n 16-Lead MSOP Package
APPLICATIONS
n Automotive n Industrial n Constant Current Source n Current Limited Constant Voltage Source
TYPICAL APPLICATION 4W Boost Automotive LED Driver LED Current vs VIN
68μH VOUT 120 VIN VIN = 6V AND ABOVE 6V TO 30V 1μF 4.7μF 100 SW ANODE CATHODE VIN ISP 80 1M 2.49Ω 100k SHDN 60 /UVLO ISN 1M 243k LT3519 1M VREF 40 LED CURRENT (mA) FB CTRL 38V LED 29.4k 100mA 137k 20 OPENLED 0 0 10 20 30 GND PWM VIN (V) M1 3519 TA01b PWM 3519 TA01a 3519fa 1