1. Products
  2. Power Management
  3. Switching Regulators
  4. SEPIC Regulators
  5. LTC3805-5

Data Sheet
JP
User Guides
2 View All

Overview

Features and Benefits

  • VIN and VOUT Limited Only by External Components
  • 4.5V Undervoltage Lockout Threshold
  • Adjustable Slope Compensation
  • Adjustable Overcurrent Protection with Automatic Restart
  • Adjustable Operating Frequency (70kHz to 700kHz) With One External Resistor
  • Synchronizable to an External Clock
  • ±1.5% Reference Accuracy
  • Only 100mV Current Sense Voltage Drop
  • RUN Pin with Precision Threshold and Adjustable Hysteresis
  • Programmable Soft-Start with One External Capacitor
  • Low Quiescent Current: 360μA
  • Small 10-Lead MSOP and 3mm × 3mm DFN

Product Details

The LTC3805-5 is a current mode DC/DC controller designed to drive an N-channel MOSFET in flyback, boost and SEPIC converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from overload and short-circuit conditions. Soft-start can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature.

The LTC3805-5 provides ±1.5% output voltage accuracy and consumes only 360μA of quiescent current during normal operation and only 40μA during micropower startup. Using a 9.5V internal shunt regulator, the LTC3805-5 can be powered from a high VIN through a resistor or it can be powered directly from a low impedance DC voltage from 4.7V to 8.8V.

The LTC3805-5 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.


 Turn On Voltage
LTC3805 8.4V
LTC3805-5 4.5V

Applications

  • Automotive Power Supplies
  • Telecom Power Supplies
  • Isolated Electronic Equipment
  • Auxiliary/Housekeeping Power Supplies
  • Power over Ethernet

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 (2)

Documentation & Resources

  • View All (9)
  • Data Sheets (1)
  • Reliability Data (1)
  • User Guides (2)
  • Design Notes (2)
  • Press Releases (2)
  • Technical Articles (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

    LTC3805-5 & LT1797 Demo Circuit - Positive-to-Negative Cuk Converter (8-16V to -12V @ 3A)
    LTC3805-5 Demo Circuit - Adjustable Frequency Current Mode Flyback Controller (18-36V to -100V @ 50mA)

    Models for the following parts are available in LTspice:

    LTC3805
    LTC3805-5

    Product Recommendations

    LTC3805-5 Companion Parts

    Recommended Suggested Oscillator

    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
    LTC3805EDD-5#PBF Material Declaration Reliability Data 10-Lead DFN (3mm x 3mm w/ EP)
    LTC3805EDD-5#TRPBF Material Declaration Reliability Data 10-Lead DFN (3mm x 3mm w/ EP)
    LTC3805EMSE-5#PBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805EMSE-5#TRPBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805HMSE-5#PBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805HMSE-5#TRPBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805IDD-5#PBF Material Declaration Reliability Data 10-Lead DFN (3mm x 3mm w/ EP)
    LTC3805IDD-5#TRPBF Material Declaration Reliability Data 10-Lead DFN (3mm x 3mm w/ EP)
    LTC3805IMSE-5#PBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805IMSE-5#TRPBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805MPMSE-5#PBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    LTC3805MPMSE-5#TRPBF Material Declaration Reliability Data 10-Lead MSOP w/ EP
    Wafer Fabrication Data R421 Reliability Data

    PCN-PDN Information

    Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.

    Select Model for PCN Information
    • LTC3805EMSE-5#PBF Production
    • LTC3805EMSE-5#TRPBF Production
    • LTC3805HMSE-5#PBF Production
    • LTC3805HMSE-5#TRPBF Production
    • LTC3805IMSE-5#PBF Production
    • LTC3805IMSE-5#TRPBF Production
    • LTC3805MPMSE-5#PBF Production
    • LTC3805MPMSE-5#TRPBF Production

    Support & Discussions

    LTC3805-5 Discussions

    LTC3805-5 seems working incorrectly
    All LTC3805-5 Discussions
    LTC3805-5 Contact ADI Technical Support »
    LTC3805-5 Ask your question »
    LTC3805-5 Contact ADI Technical Support » LTC3805-5 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.

    •