1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. External Power Switch Buck Controllers
  6. LT3740

Data Sheet
PDF
JP
User Guides
1 View All

Overview

Features and Benefits

  • Wide VIN Range: 2.2V to 22V
  • Internal Boost Provides 6V Gate Drive For VIN Down to 2.2V
  • No Sensing Resistor Required
  • Dual N-Channel MOSFET Synchronous Drive
  • Valley Current Mode Control
  • Optimized for High Step-Down Ratio
  • Power Good Output Voltage Monitor
  • 0.8V Reference
  • Three Pin-Selected Current Limit Levels
  • Constant Switching Frequency: 300kHz
  • Programmable Soft-Start
  • Output Voltage Tracking
  • Available in 16-Pin 5mm × 3mm DFN

Product Details

The LT3740 is a synchronous step-down switching regulator controller that drives N-channel power MOSFET stages. The controller uses valley current mode architecture to achieve very low duty cycles with excellent transient response without requiring a sense resistor.

The LT3740 includes an internal step-up converter to provide a bias 7.8V higher than the input voltage for the drive. This enables the part to work from an input voltage as low as 2.2V.

The XREF pin is an external reference input that allows the user to override the internal 0.8V feedback reference with any lower value, allowing full control of the output voltage during operation, output voltage tracking or soft-start.

The LT3740 has three current limit levels that can be chosen by connecting the RANGE pin to ground, open, and input respectively.

Applications

  • Notebook and Palmtop Computers, PDA
  • Portable Instruments
  • Distributed Power Systems

Product Categories

Comparable Parts Click to see all in Parametric Search

Product Lifecycle icon-recommended 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 (1)

Documentation & Resources

  • View All (4)
  • Data Sheets (1)
  • Reliability Data (1)
  • User Guides (1)
  • Design Notes (1)
    • Document Type

    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.

    LTspice

    LTspice Simulations

    LT3740 Demo Circuit - Wide Operating Range No Rsense Synchronous Step-Down Controller (5V to 1.8V @ 10A)

    Models for the following parts are available in LTspice:

    LT3740

    Product Recommendations

    LT3740 Companion Parts

    Recommended Related Parts

    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.View our quality and reliability program and certifications for more information.

    Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
    LT3740EDHC#PBF Material Declaration Reliability Data 16-Lead DFN (5mm x 3mm w/ EP)
    LT3740EDHC#TRPBF Material Declaration Reliability Data 16-Lead DFN (5mm x 3mm w/ EP)
    Wafer Fabrication Data R365 Reliability Data

    Support & Discussions

    LT3740 Contact ADI Technical Support »
    LT3740 Ask your question »
    LT3740 Contact ADI Technical Support » LT3740 Ask your question »

    Sample & Buy


    Ordering FAQs


    See our Ordering FAQs for answers to questions about online orders, payment options and more.

     

    Buy Now Pricing


    (**) Displayed Buy Now Price and Price Range is based on small quantity orders.

     

    List Pricing


    (*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

     

    Lead Times


    Please see the latest communication from our CCO regarding lead times.

     

    Sampling


    Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.


    Price Table Help

     

    Evaluation Boards

    Pricing displayed is based on 1-piece.

    Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

    Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.

    •