LTC3732 - 3-Phase, 5-Bit VID, 600kHz, Synchronous Buck Switching Regulator Controller

Features

  • 3-Phase Controller with Onboard MOSFET Drivers
  • ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
  • 4.5V </= VCC </= 7V; 4.5V </= VIN </= 32V
  • Differential Amplifier Accurately Senses VOUT
  • Reduced Input and Output Capacitance
  • Reduced Power Supply Induced Noise
  • VID DAC Programmable from 1.1V to 1.85V (VRM9.0/9.1)
  • ±10% Power Good Output Indicator
  • 250kHz to 600kHz 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
  • Small 36-Lead Narrow (0.209 inch) SSOP Package
  • QFN 5mm x 7mm 38-Lead Package

Typical Application

LTC3732 Typical Application

Description

The LTC3732 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 3-phase controller drives its output stages with 120° phase separation at frequencies of up to 600kHz 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 high 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 side 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.

LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode, OPTI-LOOP and PolyPhase are registered trademarks of Linear Technology Corporation. Stage Shedding is a trademark of Linear Technology Corporation.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC3732CG#PBF SSOP-36 G C 05-08-1640 (G36) Yes
LTC3732CG#TRPBF SSOP-36 G C 05-08-1640 (G36) Yes
LTC3732CUHF#PBF 5x7 QFN-38 UHF C 05-08-1701 Yes
LTC3732CUHF#TRPBF 5x7 QFN-38 UHF C 05-08-1701 Yes


LTC3732 Package Drawing
LTC3732 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3732CG#PBF SSOP-36 C $5.18 $4.35 Yes
LTC3732CG#TRPBF SSOP-36 C $4.45 Yes
LTC3732CUHF#PBF 5x7 QFN-38 C $5.18 $4.35 Yes
LTC3732CUHF#TRPBF 5x7 QFN-38 C $4.45 Yes
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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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC440A LTC3732CG | 3-Phase, CPU Core Power Supply, 5V to 20V Input, VRM9.0 @ 65A Max Contact Factory
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Click here to view our complete list of demo boards

Applications

  • Desktop Computers
  • High Performance Notebook Computers
  • High Output Current DC/DC Power Supplies

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC3732

Technical Support