DC1205A Datasheet, PDF (1/24 Pages) Linear Integrated Systems – 500mA Wide Input Voltage Range Step-Down LED Driver with 10:1 Dimming

LT3592
500mA Wide Input Voltage
Range Step-Down LED Driver
with 10:1 Dimming
FEATURES
DESCRIPTION
n _{Wide Input Voltage Range}
Operation from 3.6V to 36V
n _{Resistor Adjustable 400kHz–2.2MHz Switching}
Frequency
n _{Shorted and Open LED Protected}
n _{Internal Switch Current Sense Resistor}
n _{External Resistor Programs LED Current, Pin}
Selects 10:1 Ratio
n _{50mA/500mA LED Current Settings}
n _{Catch Diode Current Sense to Prevent Runaway at}
High V_IN
n _{Small Thermally Enhanced 10-Lead DFN}
(2mm × 3mm) and MSOP-10 Packages
APPLICATIONS
n _{Automotive Signal Lighting}
n _{Industrial Lighting}
n _{Constant-Current, Constant Voltage Supplies}
The LT^®3592 is a fixed frequency step-down DC/DC con-
verter designed to operate as a constant-current source.
An external sense resistor monitors the output current
allowing accurate current regulation, ideal for driving
high current LEDs. The output current can be dimmed
by a factor of 10 using an external signal for nighttime
brake lights.
The high switching frequency offers several advantages by
permitting the use of a small inductor and small ceramic
capacitors. Small components combined with the LT3592’s
10-pin DFN leadless surface mount package save space and
cost versus alternative solutions. The constant switching
frequency combined with low-impedance ceramic capaci-
tors result in low, predictable output ripple.
A wide input voltage range of 3.6V to 36V makes the
LT3592 useful in a variety of applications. Current mode
PWM architecture provides fast transient response and
cycle-by-cycle current limiting. Thermal shutdown provides
additional protection.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
50/500mA Two Series Red LED Driver
V_IN
7V TO 32V
V_IN
BOOST
1μF
LT3592
SW
0.1μF _10μH
ON
BRAKE
140k
900kHz
DA
CAP
SHDN
BRIGHT OUT
R_T
GND ^VFB
+
200/20mV
–
51k
10k
0.4Ω
4.7μF
3592 TA01a
Efficiency for 2 Red LEDs, L = 10μH, 900kHz
100
95
90
85
80
75
70
65
60
55
50
4
BRIGHT 500mA
8 12 16 20 24 28
INPUT VOLTAGE (V)
3592 TA01b
3592fc
1