LED Driver. LT3598 Datasheet

LT3598 Driver. Datasheet pdf. Equivalent

Part LT3598
Description 6-String 30mA LED Driver
Feature www.DataSheet4U.com FEATURES n n n n n n n n n n n n n n LT3598 6-String 30mA LED Driver with 1.5%.
Manufacture Linear Technology
Total Page 20 Pages
Datasheet
Download LT3598 Datasheet



LT3598
www.DataSheet4U.com
LT3598
6-String 30mA LED Driver
with 1.5% Current Matching
FEATURES
DESCRIPTION
n True Color PWM™ Dimming Delivers Up to 3000:1
Dimming Ratio
n Drives Six Strings of LEDs at Up to 30mA
n 1.5% Accurate LED Current Matching
n Wide Input Voltage Range: 3.2V to 30V
n Output Voltage Up to 44V
n Regulates Current Even When VIN > VOUT
n Disconnects LEDs in Shutdown
n Programmable Open LED Protection (Regulated)
n OPENLED Alert Pin
n Programmable LED Current Derating
n Adjustable Frequency: 200kHz to 2.5MHz
n Synchronizable to an External Clock
n Parallel Channels for Higher Current per LED String
n Thermally Enhanced 4mm × 4mm QFN Package
APPLICATIONS
n Notebook Computer Display
n Medium Size Displays
n Automotive LCD Display
The LT®3598 is a fixed frequency step-up DC/DC converter
designed to drive up to six strings of LEDs at an output
voltage up to 44V. LED dimming can be achieved with
analog dimming on the CTRL pin, and with pulse width
modulation dimming on the PWM pin. The LT3598 accu-
rately regulates LED current even when the input voltage
is higher than the LED output voltage. The switching fre-
quency is programmable from 200kHz to 2.5MHz through
an external resistor.
Additional features include programmable overvoltage
protection, switching frequency synchronization to an
external clock, LED current derating based on junction
temperature and/or LED temperature, LED string disable
control, OPENLED alert pin and output voltage limiting
when all LED strings are disconnected. The LT3598 is
available in a thermally enhanced 24-pin (4mm × 4mm)
QFN package.
LT, LTC and LTM 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, 7321203.
TYPICAL APPLICATION
PVIN
8V TO 40V
90% Efficient LED Driver for 60 White LEDs
10μH
2.2μF
VIN
5V
2.2μF
SW
VIN
100k
OPENLED
SHDN SHDN
PWM
SYNC
PWM
SYNC
LT3598
VOUT
VO_SW
FB
1.00M
30.9k
51.1k
10k
60.4k
100k
RT
VREF
CTRL
TSET ISET SS
LED1
LED2
LED3
LED4
LED5
LED6
GND VC
47pF
100k
14.7k
10nF
2.61k
15nF
LED Current Matching
4.7μF
20mA
1.5
ALL SIX LED STRINGS
1.0
0.5
0
–0.5
–1.0
–1.5
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3598 TA01b
3598 TA01a
3598f
1



LT3598
LT3598www.DataSheet4U.com
ABSOLUTE MAXIMUM RATINGS
(Note 1)
SHDN ................................................................VIN + 3V
VIN, OPENLED...........................................................30V
SW Voltage ...............................................................45V
VOUT, VO_SW Voltage .................................................44V
LED1 to LED6............................................................44V
PWM, SYNC, CTRL, RT, SS, VC ...................................6V
VREF, FB Voltage..........................................................6V
ISET, TSET.....................................................................6V
Operating Junction Temperature Range
(Note 2).................................................. –40°C to 125°C
Maximum Junction Temperature........................... 125°C
Storage Temperature Range................... –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
24 23 22 21 20 19
LED1 1
LED2 2
LED3 3
LED4 4
LED5 5
LED6 6
18 VREF
17 SS
16 RT
25
15 PWM
14 SYNC
13 NC
7 8 9 10 11 12
UF PACKAGE
24-LEAD (4mm × 4mm) PLASTIC QFN
TJMAX = 125°C, θJA = 37°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT3598EUF#PBF
LT3598EUF#TRPBF
3598
24-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C
LT3598IUF#PBF
LT3598IUF#TRPBF
3598
24-Lead (4mm × 4mm) Plastic QFN –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 5V, VSHDN = VIN unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Minimum Operating Voltage
3 3.2
V
Maximum Operating Voltage
30 V
Reference Voltage
1.216 1.230 1.260
l 1.210
1.260
V
V
Reference Voltage Line Regulation
Maximum VREF Pin Current
FB Pin Bias Current
FB Error Amp Transconductance
3 < VIN < 30V, VC = 0.3V
Out of Pin
VFB = 1.230V (Note 3)
ΔI = 5μA
0.01 0.03
%/V
200 μA
100 250
nA
300 μmhos
FB Error Amp Voltage Gain
600 V/V
FB Pin Voltage
1.22 1.24 1.26
V
Current Loop Amp Transconductance
21 μmhos
3598f
2





@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)