LT3757/LT3757A
Boost, Flyback, SEPIC and
Inverting Controller
Fea T Descrip T
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Wide Input Voltage Range: 2.9V to 40V The LT 3757/LT3757A are wide input range, current
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Positive or Negative Output Voltage Programming mode, DC/DC controllers which are capable of generating
with a Single Feedback Pin either positive or negative output voltages. They can be
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Current Mode Control Provides Excellent Transient configured as either a boost, flyback, SEPIC or inverting
Response converter. The LT3757/LT3757A drive a low side external
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Programmable Operating Frequency (100kHz to N-channel power MOSFET from an internal regulated 7.2V
1MHz) with One External Resistor supply. The fixed frequency, current-mode architecture
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Synchronizable to an External Clock results in stable operation over a wide range of supply
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Low Shutdown Current < 1A and output voltages.
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Internal 7.2V Low Dropout Voltage Regulator
The operating frequency of LT3757/LT3757A can be set
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Programmable Input Undervoltage Lockout with
with an external resistor over a 100kHz to 1MHz range,
Hysteresis
and can be synchronized to an external clock using the
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Programmable Soft-Start
SYNC pin. A low minimum operating supply voltage of
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Small 10-Lead DFN (3mm 3mm) and Thermally
2.9V, and a low shutdown quiescent current of less than
Enhanced 10-Pin MSOP Packages
1A, make the LT3757/LT3757A ideally suited for battery-
operated systems.
a T
The LT3757/LT3757A feature soft-start and frequency
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Automotive and Industrial Boost, Flyback, SEPIC and
foldback functions to limit inductor current during start-
Inverting Converters
up and output short-circuit. The LT3757A has improved
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Telecom Power Supplies
load transient performance compared to the LT3757.
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Portable Electronic Equipment
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and No R and ThinSOT are trademarks of Analog Devices, Inc. All other trademarks are the
SENSE
property of their respective owners.
Typical a T
High Efficiency Boost Converter
Efficiency
V
IN
100
8V TO 16V
10F
200k V
25V IN
90
10H
X5R
SHDN/UVLO
V = 8V
V IN
OUT
80
24V
43.2k
V = 16V
2A
LT3757 IN
SYNC GATE 70
226k
SENSE
60
RT
+ 47F
SS
FBX
35V
50
GND
V INTV
CC
C
2
41.2k
16.2k
300kHz
40
22k
4.7F 10F
0.1F 10V 0.01 25V
30
X5R X5R
6.8nF
0.001 0.01 0.1 1 10
OUTPUT CURRENT (A)
3757 TA01b
3757 TA01a
3757afe
1
For more information www.linear.com/LT3757
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLT3757/LT3757A
a Te Maxi Mu M r a T (Note 1)
Operating Temperature Range (Notes 2, 8)
V , SHDN/UVLO (Note 6) .........................................40V
IN
LT3757E/LT3757AE............................ 40C to 125C
INTV ....................................................V + 0.3V, 20V
CC IN
LT3757I/LT3757AI ............................. 40C to 125C
GATE ........................................................ INTV + 0.3V
CC
LT3757H/LT3757AH ........................... 40C to 150C
SYNC ..........................................................................8V
LT3757MP/LT3757AMP ..................... 55C to 150C
V , SS .........................................................................3V
C
Storage Temperature Range
RT ............................................................................1.5V
DFN .................................................... 65C to 125C
SENSE ....................................................................0.3V
MSOP ................................................ 65C to 150C
FBX ................................................................. 6V to 6V
Lead Temperature (Soldering, 10 sec)
MSOP ...............................................................300C
p in c F T
TOP VIEW
TOP VIEW
V 1 10 V
C IN
V 1 10 V
IN
C
FBX 2 9 SHDN/UVLO
FBX 2 9 SHDN/UVLO
11 SS 3 11 8 INTV
SS 3 8 INTV
CC
CC
RT 4 7 GATE
RT 4 7 GATE
SYNC 5 6 SENSE
SYNC 5 6 SENSE
MSE PACKAGE
10-LEAD PLASTIC MSOP
DD PACKAGE
T = 150C, = 40C/W
JMAX JA
10-LEAD (3mm 3mm) PLASTIC DFN
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
T = 125C, = 43C/W
JMAX JA
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
o r Der i n F Ma T