Features and Benefits

  • 3-Phase Current Mode Controller with Onboard MOSFET Drivers
  • ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
  • ±2% VREF Accuracy Over Temperature Up to 140°C
  • Reduced Power Supply Induced Noise
  • ±10% Power Good Output Indicator
  • 225kHz to 680kHz Per Phase, PLL, Fixed Frequency
  • PWM, Stage Shedding or Burst Mode Operation
  • OPTI-LOOP Compensation Minimizes COUT
  • Adjustable Soft-Start Current Ramping
  • Short-Circuit Shutdown Timer with Defeat Option
  • Overvoltage Soft Latch
  • Adjustable Undervoltage Lockout Threshold
  • Selectable Phase Output for Up to 12-Phase Operation
  • Available in 36-Pin Narrow (0.209") SSOP and 5mm × 5mm QFN Packages

Product Details

The LTC3731H is a PolyPhase synchronous step-down switching regulator controller that drives all N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The LTC3731H is rated for operation up to 140°C junction temperature. The 3-phase controller drives its output stages with 120° phase separation at frequencies up to 680kHz per phase to minimize the RMS current losses in both the input and output filter capacitors. The 3‑phase technique effectively triples the fundamental frequency, improving transient response while operating each controller at an optimal frequency for efficiency and ease of thermal design. Light load efficiency is optimized by using a choice of output Stage Shedding or Burst Mode operation.

The precision reference supports output voltages from 0.6V to 6V. Current foldback provides protection for the external MOSFETs under short-circuit or overload conditions. Please refer to the LTC3731 data sheet for 0°C to 70°C and –40°C to 85°C rated versions.


  • Automotive and Industrial Power Supplies
  • High Output Current DC/DC 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.

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:


Product Recommendations

LTC3731H 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.

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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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