LTC3874 - PolyPhase Step-Down Synchronous Slave Controller with Sub-Milliohm DCR Sensing

Features

  • Phase Extender for High Phase Count Voltage Rails
  • Accurate Phase-to-Phase Current Sharing
  • Sub-Milliohm DCR Current Sensing
  • Phase-Lockable Fixed Frequency 250kHz to 1MHz
  • Immediate Response to Master IC's Fault
  • Up to 12 Phase Operation
  • Wide VIN Range: 4.5V to 38V
  • VOUT Up to 5.5V
  • Proprietary Current Mode Control Loop
  • Programmable CCM/DCM Operation
  • Programmable Phase Shift Control
  • Dual N-Channel MOSFET Gate Drivers
  • 28-Lead (4mm × 5mm) QFN Package

Typical Application

LTC3874 Typical Application
LTC3874 Typical Application

Description

The LTC®3874 is a dual PolyPhase® current mode synchronous step-down slave controller. It enables high current, multi-phase applications when paired with a companion master controller by extending the phase count. Compatible master controllers include the LTC3866, LTC3875 and LTC3774. The LTC3874 employs a unique architecture that enhances the signal-to-noise ratio of the current sense signal, allowing the use of sub-milliohm DC resistance power inductors to maximize efficiency while reducing switching jitter. Its peak current mode architecture allows for accurate phase to phase current sharing even for dynamic loads.

Effectively working with a master controller, the LTC3874 supports all the programmable features as well as fault protection. The constant operating frequency can be synchronized to an external clock or linearly programmed from 250KHz to 1MHz.

Packaging

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

QFN-28

LTC3874 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC3874EUFD#PBF QFN 28 E $3.53 $2.47 View
LTC3874EUFD#TRPBF QFN 28 E $2.53 View
LTC3874IUFD#PBF QFN 28 I $3.79 $2.65 View
LTC3874IUFD#TRPBF QFN 28 I $2.71 View
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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.

Click here to view our complete list of demo boards

Applications

  • High Current Distributed Power Systems
  • Telecom, Datacom, and Storage Systems
  • Intelligent Energy Efficient Power Regulation

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Design Tools

LTspiceIV

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Models for the following parts are available in LTspice IV:
LTC3874

Technical Support