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Data Sheet Rev. C
JP
User Guides
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Alternative Parts

LTC3873-5
LTC3873-5

No RSENSE™ Constant Frequency Current Mode Boost/Flyback/SEPIC DC/DC Controller

Overview

Features and Benefits

  • VIN and VOUT Limited Only by External Components
  • Internal or Programmable External Soft-Start
  • Constant Frequency 200kHz Operation
  • Adjustable Current Limit
  • Current Sense Resistor Optional
  • Maximum 60V on SW Node with RDS(ON) Sensing
  • ±1.5% Voltage Reference Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Low Quiescent Current: 300µA
  • Low Profile (1mm) ThinSOT™ and (0.75mm) 2mm × 3mm DFN Package

Product Details

The LTC3873 is a constant frequency, current mode, boost, flyback or SEPIC DC/DC controller that drives an N-channel power MOSFET in high input and output voltage converter applications. Soft-start can be programmed using an external capacitor.

The LTC3873 provides ±1.5% output voltage accuracy and consumes only 300μA quiescent current during normal operation and only 55μA during micropower start-up. Using a 9.3V internal shunt regulator, the LTC3873 can be powered from a high input voltage through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less.

The LTC3873 is available in 8-lead ThinSOT and 2mm x 3mm DFN packages.

 


 LTC3873 LTC3873-5
VCC UV+ 8.4V 4.1V
VCC UV– 4V 2.9V


APPLICATIONS

  • Telecom Power Supplies
  • 42V and 12V Automotive Power Supplies
  • Portable Electronic Equipment

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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

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  • Data Sheets (1)
  • Reliability Data (1)
  • User Guides (1)
  • Press Releases (1)
  • 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

    LTC3873 Demo Circuit - No Rsense Constant Frequency Current Mode Boost/Flyback/SEPIC Controller (48V to 3.3V @ 3A)

    Models for the following parts are available in LTspice:

    LTC3873
    LTC3873-5

    Product Recommendations

    LTC3873 Companion Parts

    Recommended µModule Regulator

    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
    LTC3873EDDB#TRMPBF Material Declaration Reliability Data 8-Lead DFN (3mm x 2mm w/ EP)
    LTC3873EDDB#TRPBF Material Declaration Reliability Data 8-Lead DFN (3mm x 2mm w/ EP)
    LTC3873ETS8#TRMPBF Material Declaration Reliability Data 8-Lead SOT-23
    LTC3873ETS8#TRPBF Material Declaration Reliability Data 8-Lead SOT-23
    Wafer Fabrication Data R421 Reliability Data

    Support & Discussions

    LTC3873 Discussions

    LTC3872,3 series Frequency Current Mode Boost DC/DC Controller
    All LTC3873 Discussions
    LTC3873 Contact ADI Technical Support »
    LTC3873 Ask your question »
    LTC3873 Contact ADI Technical Support » LTC3873 Ask your question »

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