EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
UD PACKAGE
16-LEAD (3mm 3mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 68°C/W,
θ
JC
= 4.2°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LT3756EMSE#PBF
LT3756IMSE#PBF
LT3756EMSE-1#PBF
LT3756IMSE-1#PBF
LT3756EMSE-2#PBF
LT3756IMSE-2#PBF
LT3756HMSE-2#PBF
LT3756EUD#PBF
LT3756IUD#PBF
LT3756EUD-1#PBF
LT3756IUD-1#PBF
LT3756EUD-2#PBF
LT3756IUD-2#PBF
TAPE AND REEL
LT3756EMSE#TRPBF
LT3756IMSE#TRPBF
LT3756EMSE-1#TRPBF
LT3756IMSE-1#TRPBF
LT3756EMSE-2#TRPBF
LT3756IMSE-2#TRPBF
LT3756HMSE-2#TRPBF
LT3756EUD#TRPBF
LT3756IUD#TRPBF
LT3756EUD-1#TRPBF
LT3756IUD-1#TRPBF
LT3756EUD-2#TRPBF
LT3756IUD-2#TRPBF
PART MARKING*
3756
3756
37561
37561
37562
37562
37562
LDMQ
LDMQ
LDMR
LDMR
LFKB
LFKB
PACKAGE DESCRIPTION
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
16-Lead (3mm
×
3mm) Plastic QFN
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/
This product is only offered in trays. For more information go to:
http://www.linear.com/packaging/
375612fb
LT3756/LT3756-1/LT3756-2
elecTrical characTerisTics
PARAMETER
V
IN
Minimum Operating Voltage
V
IN
Shutdown I
Q
V
IN
Operating I
Q
(Not Switching)
V
REF
Voltage
V
REF
Line Regulation
SENSE Current Limit Threshold
SENSE Input Bias Current
SS Pull-Up Current
Error Amplifier
ISP/ISN Full-Scale Current Sense Threshold
ISP/ISN Current Sense Threshold at CTRL = 0V
CTRL Pin Range for Current Sense Threshold Adjustment
CTRL Input Bias Current
LED Current Sense Amplifier Input Common Mode Range (V
ISN
)
ISP/ISN Short-Circuit Threshold
ISP/ISN Short-Circuit Fault Sensing Common Mode Range (V
ISN
)
ISP/ISN Input Bias Current (Combined)
LED Current Sense Amplifier g
m
VC Output Impedance
VC Standby Input Bias Current
FB Regulation Voltage (V
FB
)
FB Amplifier g
m
FB Pin Input Bias Current
FB Open LED Threshold
FB Overvoltage Threshold
VC Current Mode Gain – (∆V
VC
/∆V
SENSE
)
Oscillator
Switching Frequency
Minimum Off-Time
Linear Regulator
INTV
CC
Regulation Voltage
Dropout (V
IN
– INTV
CC
)
INTV
CC
Undervoltage Lockout
INTV
CC
Current Limit
INTV
CC
Current in Shutdown
SHDN/UVLO
= 0V, INTV
CC
= 7V
I
INTVCC
= –10mA, V
IN
= 7V
3.9
14
7
7.15
1
4.1
17
8
4.3
23
12
7.3
V
V
V
mA
µA
375612fb
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V,
SHDN/UVLO
= 24V, CTRL = 2V, PWM = 5V, unless otherwise
noted.
CONDITIONS
V
IN
Tied to INTV
CC
SHDN/UVLO
= 0V, PWM = 0V
SHDN/UVLO
= 1.15V, PWM = 0V
PWM = 0V
100µA ≤ I
VREF
≤ 0µA
6V ≤ V
IN
≤ 100V
l
l
l
MIN
TYP
0.1
1.4
MAX
6
1
5
1.7
2.045
118
13
103
–7
1.1
100
100
200
3
UNITS
V
µA
µA
mA
V
%/V
mV
µA
µA
mV
mV
V
nA
V
mV
V
µA
µA
µS
kΩ
1.965
98
8
2.00
0.006
108
40
10
100
–9.5
50
Current Out of Pin
Current Out of Pin
FB = 0V, ISP = 48V
CTRL = 0V, FB = 0V, ISP = 48V
l
l
96
–12
0
2.9
115
Current Out of Pin
l
ISN = 0V
l
150
55
0
120
15000
0
PWM = 5V (Active), ISP = ISN = 48V
PWM = 0V (Standby), ISP = ISN = 48V
V
(ISP
– ISN)
= 100mV
0.1
1V < VC < 2V
PWM = 0V
l
–20
1.220
1.232
1.250
1.250
480
40
V
FB
–
65mV
V
FB
+
50mV
V
FB
–
50mV
V
FB
+
60mV
4
20
1.270
1.265
100
V
FB
–
40mV
V
FB
+
75mV
nA
V
V
µS
nA
V
V
V/V
ISP = ISN
FB = V
FB
, ISP = ISN
Current Out of Pin
OPENLED
Falling
(LT3756 and LT3756-2)
PWMOUT Falling
R
T
= 100k
R
T
= 10k
l
90
925
100
1000
170
125
1050
kHz
kHz
ns
LT3756/LT3756-1/LT3756-2
elecTrical characTerisTics
PARAMETER
Logic Inputs/Outputs
PWM Input High Voltage
PWM Input Low Voltage
PWM Pin Resistance to GND
PWMOUT Output Low (V
OL
)
PWMOUT Output High (V
OH
)
SHDN/UVLO
Threshold Voltage Falling
SHDN/UVLO
Rising Hysteresis
SHDN/UVLO
Input Low Voltage
SHDN/UVLO
Pin Bias Current Low
SHDN/UVLO
Pin Bias Current High
OPENLED
Output Low (V
OL
)
SYNC Pin Resistance to GND
SYNC Input High
SYNC Input Low
Gate Driver
t
r
GATE Driver Output Rise Time
t
f
GATE Driver Output Fall Time
GATE Output Low (V
OL
)
GATE Output High (V
OH
)
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:
The LT3756E, LT3756E-1 and LT3756E-2 are 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 LT3756I, LT3756I-1 and LT3756I-2 are
guaranteed to meet performance specifications over the –40°C to 125°C
operating junction temperature range. The LT3756H-2 is guaranteed to
meet performance specifications over the full –40°C to 150°C operating
junction temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
INTV
CC
–
0.05
C
L
= 3300pF
C
L
= 3300pF
35
35
0.05
ns
ns
V
V
I
VIN
Drops Below 1µA
SHDN/UVLO
= 1.15V
SHDN/UVLO
= 1.30V
I
OPENLED
= 0.5mA
(LT3756 and LT3756-2)
LT3756-1 Only
LT3756-1 Only
LT3756-1 Only
1.5
0.4
30
1.7
2.05
10
E-, I-Grades
H Grade
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V,
SHDN/UVLO
= 24V, CTRL = 2V, PWM = 5V, unless otherwise
noted.
CONDITIONS
MIN
1.5
0.4
45
INTV
CC
–
0.05
1.185
1.175
1.220
20
0.4
2.5
100
200
1.245
1.245
60
0
50
TYP
MAX
UNITS
V
V
kΩ
mV
V
V
V
mV
V
µA
nA
mV
kΩ
V
V
Note 3:
The LT3756 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum operating junction temperature
when overtemperature protection is active. Continuous operating above
the specified maximum operating junction temperature may impair device
reliability.
Note 4:
GATE and PWMOUT pins are driven either to GND or INTV
CC
by
internal switches. Do not connect these pins externally to a power supply.
