1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. Internal Power Switch Buck Regulators
  6. LTC3409A


Features and Benefits

  • 1.6V to 5.5V Input Voltage Range
  • 0.62V to 5.5V Output Voltage Range
  • Internal Soft-Start
  • Selectable 1.7MHz or 2.6MHz Constant Frequency Operation
  • Internal Oscillator Can Be Synchronized to an External Clock, 1MHz to 3MHz Range
  • High Efficiency: Up to 95%
  • 65μA Quiescent Current, Burst Mode® Operation
  • 600mA Output Current (VIN = 1.8V, VOUT = 1.2V)
  • 750mA Peak Inductor Current
  • No Schottky Diode Required
  • Low Dropout Operation: 100% Duty Cycle
  • 0.612V Reference Voltage
  • Stable with Ceramic Capacitors
  • Shutdown Mode Draws <1μA Supply Current
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Overtemperature Protection
  • Available in a Low Profile (0.75mm)
  • 8-Lead (3mm × 3mm) DFN Package

Product Details

The LTC3409A is a high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The LTC3409A improves upon the LTC3409’s light load regulation in Burst Mode operation. The output voltage is adjusted via an external resistor divider.

Fixed switching frequencies of 1.7MHz and 2.6MHz are supported. Alternatively, an internal PLL will synchronize to an external clock in the frequency range of 1MHz to 3MHz. This range of switching frequencies allows the use of small surface mount inductors and capacitors, including ceramics.

 Supply current during Burst Mode operation is only 65μA dropping to <1μA in shutdown. The 1.6V to 5.5V input voltage range makes the LTC3409A ideally suited for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd or NiMH battery-powered applications. 100% duty cycle capability provides low dropout operation, extending battery life in portable systems. Burst Mode operation can be user-enabled, increasing efficiency at light loads, further extending battery life.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Internal soft-start offers controlled output voltage rise time at startup without the need for external components.

VREF Tolerance
LTC3409 VREF Tolerance
LTC3409A ±3%


  • Cellular Phones
  • Digital Cameras
  • MP3 Players

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.

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.


Design tools for the following parts are available in LTpowerCAD:


Product Recommendations

LTC3409A 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
LTC3409AEDD#PBF Material Declaration Reliability Data 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP)
LTC3409AEDD#TRPBF Material Declaration Reliability Data 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP)
LTC3409AIDD#PBF Material Declaration Reliability Data 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP)
LTC3409AIDD#TRPBF Material Declaration Reliability Data 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP)
Wafer Fabrication Data R415 Reliability Data

Sample & Buy

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Buy Now Pricing

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List Pricing

(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



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