LT3957 - Boost, Flyback, SEPIC and Inverting Converter with 5A, 40V Switch
Features
- Wide Input Voltage Range: 3V to 40V
- Single Feedback Pin for Positive or Negative Output Voltage
- Internal 5A/40V Power Switch
- 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 5.2V Low Dropout Voltage Regulator
- Programmable Input Undervoltage Lockout with Hysteresis
- Programmable Soft-Start
- Thermally Enhanced QFN (5mm × 6mm) Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LT3957 is a wide input range, current mode DC/DC converter which is capable of generating either positive or negative output voltages. It can be configured as either a boost, flyback, SEPIC or inverting converter. It features an internal low side N-channel power MOSFET rated for 40V at 5A and driven from an internal regulated 5.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.
The operating frequency of LT3957 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 minimum operating supply voltage of 3V, and a low shutdown quiescent current of less than 1μA, make the LT3957 ideally suited for battery-powered systems.
The LT3957 features soft-start and frequency foldback functions to limit inductor current during start-up.
| Features | |
| LT3957 | - |
| LT3957A | Improved Load Transient Performance |
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 |
|---|---|---|---|---|---|
| LT3957EUHE#PBF | 5x6 QFN-36 | UHE | E | 05-08-1836 | Yes |
| LT3957EUHE#TRPBF | 5x6 QFN-36 | UHE | E | 05-08-1836 | Yes |
| LT3957IUHE#PBF | 5x6 QFN-36 | UHE | I | 05-08-1836 | Yes |
| LT3957IUHE#TRPBF | 5x6 QFN-36 | UHE | I | 05-08-1836 | Yes |
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 | |
|---|---|---|---|---|---|---|
| LT3957EUHE#PBF | 5x6 QFN-36 | E | $4.22 | $2.95 | Yes | |
| LT3957EUHE#TRPBF | 5x6 QFN-36 | E | $3.01 | Yes | ||
| LT3957IUHE#PBF | 5x6 QFN-36 | I | $4.84 | $3.39 | Yes | |
| LT3957IUHE#TRPBF | 5x6 QFN-36 | I | $3.45 | Yes | ||
| Buy Now • Request Samples | ||||||
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 |
|---|---|---|---|
| DC1544A | LT3957EUHE Demo Board | Boost, 4.5V ≤ VIN ≤ 20V, Vout = 24V @ 0.6A | $175.00 | |
| Buy Now | |||
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 | |
|---|---|---|---|---|---|---|
| LT3957IUHE#PBF | 5x6 QFN-36 | I | $4.84 | $3.39 | Yes | |
| LT3957IUHE#TRPBF | 5x6 QFN-36 | I | $3.45 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Automotive
- Telecom
- Industrial
People Who Viewed This Product Also Viewed
- LT3957A - Boost, Flyback, SEPIC and Inverting Converter with 5A, 40V Switch
- LT3757 - Boost, Flyback, SEPIC and Inverting Controller
- LT3958 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter
- LT3758 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller
- LT3580 - Boost/Inverting DC/DC Converter with 2A Switch, Soft-Start, and Synchronization
- LT3959 - Wide Input Voltage Range Boost/SEPIC/Inverting Converter with 6A, 40V Switch
- LT3759 - Wide Input Voltage Range Boost/SEPIC/Inverting Controller
- LTC1871 - Wide Input Range, No RSENSE Current Mode Boost, Flyback and SEPIC Controller
- LTC3789 - High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
- LT3579 - 6A Boost/Inverting DC/DC Converter with Fault Protection
Product Notifications
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.
Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.
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:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LT3957
LT3957A
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:
LT3957
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
