EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C, θ
JA
= 40°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LT3757EDD#PBF
LT3757IDD#PBF
LT3757EMSE#PBF
LT3757IMSE#PBF
LT3757HMSE#PBF
LT3757MPMSE#PBF
TAPE AND REEL
LT3757EDD#TRPBF
LT3757IDD#TRPBF
LT3757EMSE#TRPBF
LT3757IMSE#TRPBF
LT3757HMSE#TRPBF
LT3757MPMSE#TRPBF
PART MARKING*
LDYW
LDYW
LTDYX
LTDYX
LTDYX
LTDYX
PACKAGE DESCRIPTION
10-Lead (3mm × 3mm) Plastic DFN
10-Lead (3mm × 3mm) Plastic DFN
10-Lead (3mm × 3mm) Plastic MSOP
10-Lead (3mm × 3mm) Plastic MSOP
10-Lead (3mm × 3mm) Plastic MSOP
10-Lead (3mm × 3mm) Plastic MSOP
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 150°C
–55°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.
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/
3757fb
LT3757
elecTrical characTerisTics
PARAMETER
V
IN
Operating Range
V
IN
Shutdown I
Q
V
IN
Operating I
Q
V
IN
Operating I
Q
with Internal LDO Disabled
SENSE Current Limit Threshold
SENSE Input Bias Current
Error Amplifier
FBX Regulation Voltage (V
FBX(REG)
)
FBX Overvoltage Lockout
FBX Pin Input Current
Transconductance g
m
(∆I
VC
/∆V
FBX
)
VC Output Impedance
V
FBX
Line Regulation [∆V
FBX
/(∆V
IN
• V
FBX(REG)
)]
VC Current Mode Gain (∆V
VC
/∆V
SENSE
)
VC Source Current
VC Sink Current
Oscillator
Switching Frequency
R
T
= 41.2k to GND, V
FBX
= 1.6V
R
T
= 140k to GND, V
FBX
= 1.6V
R
T
= 10.5k to GND, V
FBX
= 1.6V
V
FBX
= 1.6V
270
300
100
1000
1.2
220
220
0.4
1.5
SS = 0V, Current Out of Pin
l
The
l
denotes the specifications which apply over the full operating temp-
erature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V,
SHDN/UVLO
= 24V, SENSE = 0V, unless otherwise noted.
CONDITIONS
SHDN/UVLO = 0V
SHDN/UVLO = 1.15V
V
C
= 0.3V, R
T
= 41.2k
V
C
= 0.3V, R
T
= 41.2k, INTV
CC
= 7.5V
l
MIN
2.9
TYP
0.1
1.6
280
MAX
40
1
6
2.2
400
120
UNITS
V
µA
µA
mA
µA
mV
µA
100
110
–65
Current Out of Pin
V
FBX
> 0V (Note 3)
V
FBX
< 0V (Note 3)
V
FBX
> 0V (Note 4)
V
FBX
< 0V (Note 4)
V
FBX
= 1.6V (Note 3)
V
FBX
= –0.8V (Note 3)
(Note 3)
(Note 3)
V
FBX
> 0V, 2.9V < V
IN
< 40V (Notes 3, 7)
V
FBX
< 0V, 2.9V < V
IN
< 40V (Notes 3, 7)
V
FBX
= 0V, V
C
= 1.5V
V
FBX
= 1.7V
V
FBX
= –0.85V
l
l
1.569
–0.816
6
7
–10
1.6
–0.80
8
11
70
230
5
0.002
0.0025
5.5
–15
12
11
1.631
–0.784
10
14
100
10
V
V
%
%
nA
nA
µS
MΩ
0.056
0.05
%/V
%/V
V/V
µA
µA
µA
330
kHz
kHz
kHz
V
ns
ns
V
V
µA
RT Voltage
Minimum Off-Time
Minimum On-Time
SYNC Input Low
SYNC Input High
SS Pull-Up Current
Low Dropout Regulator
INTV
CC
Regulation Voltage
INTV
CC
Undervoltage Lockout Threshold
INTV
CC
Overvoltage Lockout Threshold
INTV
CC
Current Limit
INTV
CC
Load Regulation (∆V
INTVCC
/ V
INTVCC
)
INTV
CC
Line Regulation ∆V
INTVCC
/(V
INTVCC
• ∆V
IN
)
Dropout Voltage (V
IN
– V
INTVCC
)
–10
7
2.6
16
7.2
2.7
0.1
17.5
40
95
–0.5
0.008
400
0.03
55
7.4
2.8
V
V
V
V
mA
mA
%
%/V
mV
Falling INTV
CC
UVLO Hysteresis
V
IN
= 40V
V
IN
= 15V
0 < I
INTVCC
< 20mA, V
IN
= 8V
8V < V
IN
< 40V
V
IN
= 6V, I
INTVCC
= 20mA
30
–0.9
3757fb
LT3757
elecTrical characTerisTics
PARAMETER
INTV
CC
Current in Shutdown
INTV
CC
Voltage to Bypass Internal LDO
Logic Inputs
SHDN/UVLO Threshold Voltage Falling
SHDN/UVLO Input Low Voltage
SHDN/UVLO Pin Bias Current Low
SHDN/UVLO Pin Bias Current High
Gate Driver
t
r
Gate Driver Output Rise Time
t
f
Gate Driver Output Fall Time
Gate V
OL
Gate 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 LT3757E is guaranteed to meet performance specifications
from the 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
LT3757I is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT3757H is guaranteed 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. The LT3757MP is 100% tested and guaranteed over the
full –55°C to 125°C operating junction temperature range.
INTV
CC
–0.05
C
L
= 3300pF (Note 5), INTV
CC
= 7.5V
C
L
= 3300pF (Note 5), INTV
CC
= 7.5V
22
20
0.05
ns
ns
V
V
V
IN
= INTV
CC
= 8V
I(V
IN
) Drops Below 1µA
SHDN/UVLO = 1.15V
SHDN/UVLO = 1.30V
1.7
2
10
l
The
l
denotes the specifications which apply over the full operating temp-
erature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V,
SHDN/UVLO
= 24V, SENSE = 0V, unless otherwise noted.
CONDITIONS
SHDN/UVLO = 0V, INTV
CC
= 8V
MIN
TYP
16
7.5
1.17
1.22
1.27
0.4
2.5
100
MAX
UNITS
µA
V
V
V
µA
nA
Note 3: The LT3757 is tested in a feedback loop which servos V
FBX
to the
reference voltages (1.6V and –0.8V) with the VC pin forced to 1.3V.
Note 4: FBX overvoltage lockout is measured at V
FBX(OVERVOLTAGE)
relative
to regulated V
FBX(REG)
.
Note 5: Rise and fall times are measured at 10% and 90% levels.
Note 6: For V
IN
below 6V, the SHDN/UVLO pin must not exceed V
IN
.
Note 7: SHDN/UVLO = 1.33V when V
IN
= 2.9V.
Note 8: The LT3757 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 operation above
the specified maximum operating junction temperature may impair device