LT3757/LT3757A - Boost, Flyback, SEPIC and Inverting Controller

Features

  • Wide Input Voltage Range: 2.9V to 40V
  • Positive or Negative Output Voltage Programming with a Single Feedback Pin
  • Current Mode Control Provides Excellent Transient Response
  • Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor
  • Synchronizable to an External Clock
  • Low Shutdown Current < 1μA
  • Internal 7.2V Low Dropout Voltage Regulator
  • Programmable Input Undervoltage Lockout with Hysteresis
  • Programmable Soft-Start
  • Small 10-Lead DFN (3mm × 3mm) and Thermally Enhanced 10-Pin MSOP Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LT3757 Typical Application
LT3757 Typical Application

Description

The LT®3757/LT3757A are wide input range, current mode, DC/DC controllers which are capable of generating either positive or negative output voltages. They can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3757/LT3757A drive a low side external N-channel power MOSFET from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.

The operating frequency of LT3757/LT3757A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A low minimum operating supply voltage of 2.9V, and a low shutdown quiescent current of less than 1μA, make the LT3757/LT3757A ideally suited for batteryoperated systems.

The LT3757/LT3757A feature soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. The LT3757A has improved load transient performance compared to the LT3757.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LT3757AEDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3757AEDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3757AEMSE#PBF MS-10E MSE E 05-08-1664 Yes
LT3757AEMSE#TRPBF MS-10E MSE E 05-08-1664 Yes
LT3757AHMSE#PBF MS-10E MSE H 05-08-1664 Yes
LT3757AHMSE#TRPBF MS-10E MSE H 05-08-1664 Yes
LT3757AIDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3757AIDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3757AIMSE#PBF MS-10E MSE I 05-08-1664 Yes
LT3757AIMSE#TRPBF MS-10E MSE I 05-08-1664 Yes
LT3757AMPMSE#PBF MS-10E MSE MP 05-08-1664 Yes
LT3757AMPMSE#TRPBF MS-10E MSE MP 05-08-1664 Yes
LT3757EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3757EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3757EMSE#PBF MS-10E MSE E 05-08-1664 Yes
LT3757EMSE#TRPBF MS-10E MSE E 05-08-1664 Yes
LT3757HMSE#PBF MS-10E MSE H 05-08-1664 Yes
LT3757HMSE#TRPBF MS-10E MSE H 05-08-1664 Yes
LT3757IDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3757IDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3757IMSE#PBF MS-10E MSE I 05-08-1664 Yes
LT3757IMSE#TRPBF MS-10E MSE I 05-08-1664 Yes
LT3757MPMSE MS-10E MSE MP 05-08-1664 No
LT3757MPMSE#PBF MS-10E MSE MP 05-08-1664 Yes
LT3757MPMSE#TR MS-10E MSE MP 05-08-1664 No
LT3757MPMSE#TRPBF MS-10E MSE MP 05-08-1664 Yes


LT3757 Package Drawing
LT3757 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3757AEDD#PBF 3x3 DFN-10 E $2.94 $2.06 Yes
LT3757AEDD#TRPBF 3x3 DFN-10 E $2.12 Yes
LT3757AEMSE#PBF MS-10E E $2.94 $2.06 Yes
LT3757AEMSE#TRPBF MS-10E E $2.12 Yes
LT3757AHMSE#PBF MS-10E H $3.66 $2.56 Yes
LT3757AHMSE#TRPBF MS-10E H $2.62 Yes
LT3757AIDD#PBF 3x3 DFN-10 I $3.16 $2.21 Yes
LT3757AIDD#TRPBF 3x3 DFN-10 I $2.27 Yes
LT3757AIMSE#PBF MS-10E I $3.16 $2.21 Yes
LT3757AIMSE#TRPBF MS-10E I $2.27 Yes
LT3757AMPMSE#PBF MS-10E MP $8.54 $5.98 Yes
LT3757AMPMSE#TRPBF MS-10E MP $6.04 Yes
LT3757EDD#PBF 3x3 DFN-10 E $2.94 $2.06 Yes
LT3757EDD#TRPBF 3x3 DFN-10 E $2.12 Yes
LT3757EMSE#PBF MS-10E E $2.94 $2.06 Yes
LT3757EMSE#TRPBF MS-10E E $2.12 Yes
LT3757HMSE#PBF MS-10E H $3.66 $2.56 Yes
LT3757HMSE#TRPBF MS-10E H $2.62 Yes
LT3757IDD#PBF 3x3 DFN-10 I $3.16 $2.21 Yes
LT3757IDD#TRPBF 3x3 DFN-10 I $2.27 Yes
LT3757IMSE#PBF MS-10E I $3.16 $2.21 Yes
LT3757IMSE#TRPBF MS-10E I $2.27 Yes
LT3757MPMSE MS-10E MP $8.54 $5.98 No
LT3757MPMSE#PBF MS-10E MP $8.54 $5.98 Yes
LT3757MPMSE#TR MS-10E MP $6.04 No
LT3757MPMSE#TRPBF MS-10E MP $6.04 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1341A LT3757EDD SEPIC Demo Board | 4.5V-36Vin; Vout = 5V @ 3A $175.00
DC1547B LT3757AEDD Boost Demo Board | Boost, 3.1V ≤ VIN ≤ 9V; VOUT = 12V @ 1.5A $150.00
DC1548A LT3757EDD Inverting (CUK) Demo Board | 7V-28Vin; Vout = -15V @ 1A $150.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3757AHMSE#PBF MS-10E H $3.66 $2.56 Yes
LT3757AHMSE#TRPBF MS-10E H $2.62 Yes
LT3757AIDD#PBF 3x3 DFN-10 I $3.16 $2.21 Yes
LT3757AIDD#TRPBF 3x3 DFN-10 I $2.27 Yes
LT3757AIMSE#PBF MS-10E I $3.16 $2.21 Yes
LT3757AIMSE#TRPBF MS-10E I $2.27 Yes
LT3757AMPMSE#PBF MS-10E MP $8.54 $5.98 Yes
LT3757AMPMSE#TRPBF MS-10E MP $6.04 Yes
LT3757HMSE#PBF MS-10E H $3.66 $2.56 Yes
LT3757HMSE#TRPBF MS-10E H $2.62 Yes
LT3757IDD#PBF 3x3 DFN-10 I $3.16 $2.21 Yes
LT3757IDD#TRPBF 3x3 DFN-10 I $2.27 Yes
LT3757IMSE#PBF MS-10E I $3.16 $2.21 Yes
LT3757IMSE#TRPBF MS-10E I $2.27 Yes
LT3757MPMSE#PBF MS-10E MP $8.54 $5.98 Yes
LT3757MPMSE#TRPBF MS-10E MP $6.04 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

  • Automotive and Industrial Boost, Flyback, SEPIC and Inverting Converters
  • Telecom Power Supplies
  • Portable Electronic Equipment

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice IV:
LT3757
LT3757A

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

Design tools for the following parts are available in LTpowerCAD:
LT3757

Technical Support