LTM4645 - 25A DC/DC Step-Down µModule Regulator


  • 4.7V to 15V Input Voltage Range
  • 0.6V to 1.8V Output Voltage Range
  • 25A DC Output Current
  • 1.2% Total DC Output Voltage Error (–40°C to 125°C)
  • High Reliability N + 1 Phase Redundancy Supported
  • Internal or External Control Loop Compensation
  • Differential Remote Sense Amplifier for Precision Regulation
  • Current Mode Control/Fast Transient Response
  • Multiphase Current Sharing Up to 150A
  • Built-In Temperature Monitoring
  • Selectable Pulse-Skipping, Burst Mode® Operation
  • Soft-Start/Voltage Tracking
  • Frequency Synchronization
  • Output Overvoltage Protection
  • Output Overcurrent Foldback Protection
  • 9mm × 15mm × 3.51mm BGA Package

Typical Application

LTM4645 Typical Application
LTM4645 Typical Application


The LTM®4645 is a 25A output switching mode step-down DC/DC µModule® (power module) regulator. Included in the package are the switching controller, power FETs, inductor and all supporting components. Operating over an input voltage range of 4.7V to 15V, the LTM4645 supports an output voltage range of 0.6V to 1.8V, set by a single external resistor. Only a few input and output capacitors are needed.

Its high efficiency design delivers about 86% efficiency from 12V input to 1.0V output with 25A continuous load current. High switching frequency and a current-mode architecture enable a very fast transient response to line and load changes without sacrificing stability. The device supports frequency synchronization, programmable multiphase operation, N+1 phase redundancy, and output voltage tracking for supply rail sequencing.

Fault protection features include overvoltage and overcurrent protection. The power module is offered in a space saving 9mm × 15mm × 3.51mm BGA package. The LTM4645 is available with SnPb (BGA) or RoHS compliant terminal finish.



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

Part Number Package Code Temp Package
LTM4645EY#PBF 15.00mm x 9.00mm x 3.51mm BGA E 05-08-1542 Yes
LTM4645IY 15.00mm x 9.00mm x 3.51mm BGA I 05-08-1542 No
LTM4645IY#PBF 15.00mm x 9.00mm x 3.51mm BGA I 05-08-1542 Yes

LTM4645 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
LTM4645EY#PBF 15.00mm x 9.00mm x 3.51mm E $37.47 $26.23 Yes
LTM4645IY 15.00mm x 9.00mm x 3.51mm I $57.70 $40.39 No
LTM4645IY#PBF 15.00mm x 9.00mm x 3.51mm I $41.22 $28.85 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
DC2616A LTM4645 Demo Board | 50A Poly Phase Step-Down Regulator (Dual LTM4645) Contact Factory
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Click here to view our complete list of demo boards


  • Telecom, Networking and Industrial Equipment
  • Point of Load Regulation

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Design Tools


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:


The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

Design tools for the following parts are available in LTpowerCAD:
LTM4645 Parallel

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