LT3909E, LT3909I ............................. –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MSOP Package Only ............................................. 300°C
PIN CONFIGURATION
TOP VIEW
INTV
CC
V
IN
EN/UVLO
I
SET
CTRL
FB
1
2
3
4
5
6
13
GND
12 SW
11 V
OUT
10 LED1
9 LED2
8
FAULT
7 PWM
INTV
CC
V
IN
EN/UVLO
I
SET
CTRL
FB
1
2
3
4
5
6
TOP VIEW
12
11
10
9
8
7
SW
V
OUT
LED1
LED2
FAULT
PWM
13
GND
DD PACKAGE
12-LEAD (3mm × 3mm) PLASTIC DFN
θ
JA
= 43°C/W,
θ
JC
= 5.5°C/W
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
12-LEAD PLASTIC MSOP
θ
JA
= 40°C/W,
θ
JC
= 5°C/W to 10°C/W
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3909EDD#PBF
LT3909IDD#PBF
LT3909EMSE#PBF
LT3909IMSE#PBF
TAPE AND REEL
(http://www.linear.com/product/LT3909#orderinfo)
PART MARKING*
LGMY
LGMY
3909
3909
PACKAGE DESCRIPTION
12-Lead (3mm × 3mm) Plastic DFN
12-Lead (3mm × 3mm) Plastic DFN
12-Lead Plastic MSOP
12-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
LT3909EDD#TRPBF
LT3909IDD#TRPBF
LT3909EMSE#TRPBF
LT3909IMSE#TRPBF
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
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/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
3909fb
2
For more information
www.linear.com/LT3909
LT3909
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
EN/UVLO
= 12V, R
ISET
= 49.9k, V
OUT
= 24V, unless otherwise noted.
PARAMETER
Input, Bias, Reference
Input Voltage Range
V
IN
Quiescent Current (Not Switching)
V
IN
Shutdown Current
Enable/Lockout Threshold
EN/UVLO Shutdown Threshold
EN/UVLO Enable Threshold
EN/UVLO Enable Hysteresis
EN/UVLO Pin Current
V
EN/UVLO
= 0.4V
V
EN/UVLO
= 1.15V
V
EN/UVLO
= 1.3V
I
INTVCC
= 0A to 100µA
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
2.9
TYP
MAX
40
UNITS
V
µA
µA
µA
V
V
OUT
– V
LEDx
= 2V, V
CTRL
= 2.0V, PWM = 1.5V
V
EN/UVLO
= 0.4V, V
IN
= 12V
V
EN/UVLO
= 0.4V, V
IN
= 40V
I
VIN
< 10µA
Falling
l
l
600
0.3
1.5
0.4
1.180
0.6
1.215
30
1.6
0.8
2.0
0
3.0
2
0.02
l
700
2
4
1.250
V
mV
µA
µA
µA
V
MHz
%/V
%
2.4
Linear Regulator (INTV
CC
)
INTV
CC
Regulation Voltage
Oscillator
Switching Frequency
f
OSC
Line Regulation
Maximum Duty Cycle
LED Current/Control
LEDx Current (20mA)
Current Matching (20mA)
LEDx Current (50mA)
Current Matching (50mA)
LEDx Current (60mA) (Note 5)
Current Matching (60mA) (Note 5)
V
OUT
– V
LEDx
Regulation
Analog Dimming
CTRL Input Current (Out of Pin)
CTRL Latch-Off Threshold
CTRL Latch-Off Hysteresis
LEDx Current (Dimming 10:1)
PWM Dimming
PWM Input Low Threshold
PWM Input High Threshold
PWM Resistance to GND
LEDx Leakage Current (PWM = 0V)
Fault Diagnostics
FAULT
Output Low
FAULT
Leakage Current
I
FAULT
= 100µA
V
FAULT
= 5V
0.1
0.1
0.2
1
V
µA
V
LEDx
= 12V, V
OUT
= 40V
l
l
l
l
2.9
1.88
86
19.4
48.0
57.0
3.1
2.12
0.1
2.9V ≤ V
IN
≤ 40V
91
20
±0.3
50
±0.3
60
±0.3
1.3
20.6
±1.8
52.0
±1.8
63.0
±2.0
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
= 49.9k
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
= 49.9k
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
= 20.0k
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
= 20.0k
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
= 16.7k
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 1.2V, R
ISET
=16.7k
l
l
l
l
l
l
mA
%
mA
%
mA
%
V
V
CTRL
= 1V
V
CTRL
= 0.1V
Falling
Rising
V
OUT
– V
LEDx
= 1.1V, V
CTRL
= 0.1V, R
ISET
= 49.9k
1.87
0.8
75
5
15
80
10
2.03
1.1
1.2
100
0.1
200
200
85
2.19
nA
nA
mV
mV
mA
V
1.5
1
V
kΩ
µA
3909fb
For more information
www.linear.com/LT3909
3
LT3909
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
EN/UVLO
= 12V, R
ISET
= 49.9k, V
OUT
= 24V, unless otherwise noted.
PARAMETER
LEDx Short Threshold V
LEDx
(Note 6)
LEDx Open Threshold (V
OUT
– V
LEDx
)
Output Voltage
FB Regulation Voltage
FB Input Current (Out of Pin)
Switch
Switch Current Limit
Switch On-Resistance
Switch Leakage Current
Schottky Diode
Schottky Forward Voltage
I
SCHOTTKY
= 250mA
0.8
V
I
SW
= 100mA
V
SW
= 40V, V
OUT
= 40V
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
V
LEDx
Falling
MIN
5.8
TYP
6.0
0.3
MAX
6.2
0.4
1.240
100
UNITS
V
V
V
nA
A
mΩ
µA
(V
OUT
– V
LEDx
) Falling
1.190
–100
1.0
1.215
V
FB
= 1.215V
l
1.1
400
1.2
2
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
Do not apply a positive or negative voltage to INTV
CC
or I
SET
pins,
otherwise permanent damage may occur.
Note 3:
The LT3909 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 4:
The LT3909E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3909I is guaranteed over the full –40°C to 125°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 5:
The 16.7k is a 0.1% resistor to achieve exactly 60mA LED current.
Note 6:
The LED short threshold refers to the LED pin voltage with respect
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