LT3519-2_15 Datasheet, PDF (1/20 Pages) Linear Technology – LED Driver with Integrated Schottky Diode

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