Overview

Features and Benefits

  • Wide Input Voltage Range: 3.0V to 42V
  • Ultralow Quiescent Current Burst Mode® Operation:
    • <2.5µA IQ Regulating 12VIN to 3.3VOUT
    • Output Ripple <10mVP-P
  • High Efficiency 2MHz Synchronous Operation:
    • >93% Efficiency at 1A, 5VOUT from 12VIN
  • 3A Maximum Continuous Output
  • Fast Minimum Switch-On Time: 45ns
  • LT8609A Available in Fixed 3.3V and 5V Output
  • Adjustable and Synchronizable: 200kHz to 2.2MHz
  • Spread Spectrum Frequency Modulation for Low EMI
  • Allows Use of Small Inductors
  • Low Dropout
  • Peak Current Mode Operation
  • Accurate 1V Enable Pin Threshold
  • Internal Compensation
  • Output Soft-Start and Tracking
  • Small 10-Lead MSOP Package, 16-Lead MSOP Package, or 10-Lead 3mm × 3mm DFN Package with Side Wettable Flanks
  • AEC-Q100 Qualified for Automotive Applications

Product Details

The LT8609/LT8609A/LT8609B is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7µA of nonswitching quiescent current. The LT8609/LT8609A/LT8609B can deliver 3A of continuous current. Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN UVLO or to shut down the part. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% on the adjustable output parts or ±7.5% on the fixed output parts of the programmed output voltage as well as fault conditions. The LT8609A has slower switch edges for lower EMI emissions. The LT8609B operates in pulse-skipping mode only.

Pulse-Skipping Mode, Burst Mode Operation Switch Edge Speed
LT8609 Both Fast
LT8609A Both Medium
LT8609B Pulse-Skipping Fast

Applications

  • GSM Transceivers
  • General Purpose Step-Down
  • Low EMI Step-Down

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (5)

Documentation & Resources

  • View All (13)
  • Data Sheets (1)
  • Reliability Data (1)
  • User Guides (2)
  • Design Notes (2)
  • Solutions Bulletins & Brochures (3)
  • Application Notes (1)
  • Press Releases (1)
  • Technical Articles (2)
  • 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

    Models for the following parts are available in LTspice:

    LT8609
    LT8609A
    LT8609B
    LT8609S

    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

    Design tools for the following parts are available in LTpowerCAD:

    LT8609
    LT8609A
    LT8609S

    Reference Designs (2)

    Product Recommendations

    LT8609 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.

    PCN-PDN Information

    Sample & Buy


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    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.