Features and Benefits

  • 3.6V to 15V Input Voltage Range
  • ±3A Output Current per Channel
  • Up to 95% Efficiency
  • Selectable 90°/180° Phase Shift Between Channels
  • Adjustable Switching Frequency: 500kHz to 4MHz
  • VTTR = VDDQ/2 = VTT Reference
  • ±1.6% Accurate VTTR at 0.75V
  • Optimal VOUT Range: 0.6V to 3V
  • ±10mA Buffered Output Supplies VREF Reference Voltage
  • Current Mode Operation for Excellent Line and Load Transient Response
  • External Clock Synchronization
  • Short-Circuit Protected
  • Input Overvoltage and Overtemperature Protection
  • Power Good Status Outputs
  • Available in (4mm × 5mm) QFN-28 and Thermally Enhanced 28-Lead TSSOP Packages

Product Details

The LTC3634 is a high efficiency, dual-channel monolithic synchronous step-down regulator which provides power supply and bus termination rails for DDR1, DDR2, and DDR3 SDRAM controllers. The operating input voltage range is 3.6V to 15V, making it suitable for point-of-load power supply applications from a 5V or 12V input, as well as various battery powered systems.

The VTT regulated output voltage is equal to VDDQIN • 0.5. An on-chip buffer capable of driving a 10mA load provides a low noise reference output (VTTR) also equal to VDDQIN • 0.5.

The operating frequency is programmable and synchronizable from 500kHz to 4MHz with an external resistor. The two channels can operate 180° out-of-phase, which relaxes the requirements for input and output capacitance. The unique controlled on-time architecture is ideal for powering DDR applications from a 12V supply at high switching frequencies, allowing the use of smaller external components.

The LTC3634 is offered in both 28-pin 4mm × 5mm QFN and 28-pin exposed pad TSSOP packages.


  • DDR Memory Power Supplies

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)

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.


Models for the following parts are available in LTspice:



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.


Design tools for the following parts are available in LTpowerCAD:


Reference Designs (5)

Product Recommendations

LTC3634 Companion Parts

Recommended µModule Regulator

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

Sample & Buy

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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.