Overview

Features and Benefits

  • Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
  • Accurate Multiphase Current Matching
  • RSENSE or DCR Current Sensing
  • ±0.75% 0.6V Output Voltage Accuracy
  • Phase-Lockable Fixed Frequency 250kHz to 780kHz
  • High Efficiency: Up to 95%
  • Dual N-channel MOSFET Synchronous Drive
  • Wide VIN Range: 4V to 38V (40V Max) Operation
  • Wide VOUT Range: 0.6V to 12.5V Operation
  • Adjustable Soft-Start Current Ramping or Tracking
  • Foldback Output Current Limiting
  • Output Overvoltage Protection
  • Power Good Output Voltage Monitor
  • 5V Low Dropout Regulator
  • Small 28-Lead QFN and Narrow SSOP Packages

Product Details

The LTC3869 is a high performance dual synchronous step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 780kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out-of-phase.

OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. A wide 4V to 38V input supply range encompasses most battery chemistries. Independent TK/SS pins for each controller ramp the output voltage during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock.

The LTC3869 is available in low profile 4mm × 4mm and 4mm × 5mm QFN packages. The LTC3869-2 is available in an SSOP-28 package. The LTC3869 is pin-compatible with the LTC3850.

Applications

  • Server Systems
  • Telecom Systems
  • Industrial and Medical Instruments
  • High Power Battery-Operated Devices
  • DC Power Distribution Systems

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 (4)

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:

LTC3869
LTC3869-2

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:

LTC3869
LTC3869 Parallel
LTC3869-2
LTC3869-2 Parallel
ltc3869-2Parallel
ltc3869Parallel

Product Recommendations

LTC3869 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.

Discussions

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The USA 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. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


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Evaluation Boards Pricing displayed is based on 1-piece.
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.