Features and Benefits

  • High Voltage Buck Regulator:
    • 4V to 42V Operating Range
    • 1.3A Output Current
  • Input Transient Protection to 55V
  • Low Voltage Synchronous Buck Regulator:
    • 2.5V to 5.5V Input Voltage Range
    • 1.1A Output Current
  • Synchronizable, Adjustable 350kHz to 2.5MHz Switching Frequency
  • Programmable Power-On Reset Timer
  • Programmable Window Mode Watchdog Timer
  • Typical Quiescent Current: 290μA
  • Short-Circuit Robust
  • Programmable Soft-Start
  • Low Shutdown Current: IQ < 1μA
  • Thermal Shutdown
  • Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and 28-Lead TSSOP Packages

Product Details

The LT3641 is a dual channel, current mode monolithic buck switching regulator with a power-on reset and a watchdog timer. Both regulators are synchronized to a single oscillator with an adjustable frequency (350kHz to 2.5MHz). At light loads, both regulators operate in low ripple Burst Mode® to maintain high effi ciency and low output ripple.

The high voltage channel is a nonsynchronous buck with an internal 2.4A top switch that operates from an input of 4V to 42V and input transient protection to 55V. The low voltage channel operates from an input of 2.5V to 5.5V. Internal synchronous power switches provide high effi ciency without the need of external Schottky diode. Both channels have cycle-by-cycle current limit, providing protection against shorted outputs.

The power-on reset and watchdog timeout periods are both adjustable using external capacitors. The window mode watchdog timer fl ags when the μP pulses group too close together or too far apart.

The LT3641 is available in a 28-pin 4mm × 5mm QFN package and 28-pin TSSOP package. Both packages have an exposed pad for low thermal resistance.


  • Industrial Power Supplies
  • Automotive Electronic Control Units

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)

Tools & Simulations


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.

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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.


Models for the following parts are available in LTspice:


Product Recommendations

LT3641 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.

PCN-PDN Information

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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.