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  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. Internal Power Switch Buck Regulators
  6. LTC3605

Data Sheet Rev. I
JP
User Guides
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Overview

Features and Benefits

  • High Efficiency: Up to 96%
  • 5A Output Current
  • 4V to 15V VIN Range
  • Integrated Power N-Channel MOSFETs
    (70mΩ Top and 35mΩ Bottom)
  • Adjustable Frequency 800kHz to 4MHz
  • PolyPhase® Operation (Up to 12 Phases)
  • Output Tracking
  • 0.6V ±1% Reference Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Shutdown Mode Draws Less Than 15μA Supply Current
  • Available in 24-Pin (4mm × 4mm) QFN Package
  • AEC-Q100 Qualified for Automotive Applications

Product Details

The LTC3605 is a high efficiency, monolithic synchronous buck regulator using a phase lockable controlled on-time constant frequency, current mode architecture. PolyPhase operation allows multiple LTC3605 regulators to run out of phase while using minimal input and output capacitance. The operating supply voltage range is from 15V down to 4V, making it suitable for dual lithium-ion battery inputs as well as point of load power supply applications from a 12V or 5V rail.

The operating frequency is programmable from 800kHz to 4MHz with an external resistor. The high frequency capability allows the use of small surface mount inductors. For switching noise sensitive applications, it can be externally synchronized from 800kHz to 4MHz. The PHMODE pin allows user control of the phase of the outgoing clock signal. The unique constant frequency/controlled on-time architecture is ideal for high step-down ratio applications that are operating at high frequency while demanding fast transient response. Two internal phase-lock loops synchronize the internal oscillator to the external clock and also servos the regulator on-time to lock on to either the internal clock or the external clock if it’s present.


   Input Voltage Range
LTC3605 4V to 15V
LTC3605A 4V to 20V

APPLICATIONS

  • Point of Load Power Supply
  • Portable Instruments
  • Distributed Power Systems
  • Battery-Powered Equipment

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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 (6)
  • Data Sheets (1)
  • Reliability Data (1)
  • User Guides (1)
  • Design Notes (1)
  • Product Selector Card (1)
  • Press Releases (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

    LTC3605 Demo Circuit - 15V, 5A, 4MHz, Synchronous Step-down Regulator (12V to 1.8V @ 5A)

    Models for the following parts are available in LTspice:

    LTC3605
    LTC3605A

    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.

    To open the project file for this circuit:

    Step 1: Download and install LTpowerCAD on your computer.

    Step 2: Click on the link(s) in the section below to download part-specific project files.

    Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.

    LTPowerCAD

    LTpowerCAD Project Files

    LTC3605 Project - 15V, 5A Monolithic Buck Regulator (5-14V to 3.3V @ 5A)

    Design tools for the following parts are available in LTpowerCAD:

    LTC3605
    LTC3605A

    Reference Designs (7)

    Product Recommendations

    LTC3605 Companion Parts

    Recommended Related 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
    LTC3605EUF#PBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605EUF#TRPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605EUF#WPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605EUF#WTRPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605IUF#PBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605IUF#TRPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605IUF#WPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    LTC3605IUF#WTRPBF Material Declaration Reliability Data 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
    Wafer Fabrication Data R539 Reliability Data

    Support & Discussions

    LTC3605 Discussions

    RE: LTC3605 - Bootstrapping diode
    need check if buck circuit design correct -LTC3605AEUF
    All LTC3605 Discussions
    LTC3605 Contact ADI Technical Support »
    LTC3605 Ask your question »
    LTC3605 Contact ADI Technical Support » LTC3605 Ask your question »

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