1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. Digitally Programmable Regulators
  6. LTC3733


Features and Benefits

  • 3-Phase Controller with Onboard MOSFET Drivers
  • Current Mode Control Ensures Current Sharing
  • Differential Amplifier Accurately Senses VOUT
  • ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
  • Reduced Input and Output Capacitance
  • Supports Active Voltage Positioning
  • VID Programmable Output Voltage from 0.8V to 1.55V (AMD Opteron CPU)
  • 6-Phase, 90A to 120A Operation
  • Output Power Good Indicator with Adaptive Blanking
  • 210kHz to 530kHz Per Phase, PLL, Fixed Frequency
  • Synchronizable (LTC3733-1)
  • PWM, Stage Shedding or Burst Mode® Operation
  • OPTI-LOOP® Compensation Minimizes COUT
  • Adjustable Soft-Start Current Ramping
  • Short-Circuit Shutdown Timer with Defeat Option
  • No_CPU Detection
  • 36-Lead Narrow SSOP and 38-Lead (5mm × 7mm) QFN

Product Details

The LTC3733 family are PolyPhase® synchronous stepdown switching regulator controllers that drive all N-channel external power MOSFET stages in a phase-lockable, fixed frequency architecture. The 3-phase controller drives its output stages with 120° phase separation at frequencies of up to 530kHz per phase to minimize the RMS current dissipated by the ESR of both the input and output filter capacitors. The 3-phase technique effectively triples the fundamental frequency, improving transient response while operating each phase 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 technology.

A differential amplifier provides true remote sensing of both the high and low sides of the output voltage at load points.

Soft-start and a defeatable, timed short-circuit shutdown protect the MOSFETs and the load. A foldback current circuit also provides protection for the external MOSFETs under short-circuit or overload conditions. An all-“1” VID detector turns off the regulator after 1µs timeout.


  • High Performance Notebook Computers
  • Servers, Desktop Computers and Workstations

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


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Product Recommendations

LTC3733 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.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
LTC3733CG#PBF Material Declaration Reliability Data 36-Lead SSOP
LTC3733CG#TRPBF Material Declaration Reliability Data 36-Lead SSOP
LTC3733CUHF-1#PBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
LTC3733CUHF-1#TRPBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
Wafer Fabrication Data R384 Reliability Data

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Evaluation Boards

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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.