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Overview
Features and Benefits
- 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
Product Details
The LT3757/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 battery-operated systems.
The LT3757/LT3757A feature soft-start and frequency foldback functions to limit inductor current during startup and output short-circuit. The LT3757A has improved load transient performance compared to the LT3757.
Applications
- Automotive and Industrial Boost, Flyback, SEPIC and Inverting Converters
- Telecom Power Supplies
- Portable Electronic Equipment
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (4)
Documentation
Reliability Data (1)
Evaluation Kit Manuals (3)
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
Models for the following parts are available in LTspice:
LTpowerCAD
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
Reference Materials
LTspice: Using Transformers
LT3757 2.9V to 40V Boost, SEPIC, Flyback or Inverting Controller
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Discussions
LT3757 Discussions
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Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
