LTC3874-1 - PolyPhase Step-Down Synchronous Slave Controller with Sub-Milliohm DCR Sensing


  • Phase Extender for High Phase Count Voltage Rails
  • Operates with Power Blocks, DrMOS or External Gate Drivers and MOSFETs
  • 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: 4.5 to 38V
  • VOUT Range :   Up to 3.5V (LOWDCR Pin High)

Up to 5.5V (LOWDCR Pin Low) 

  • Proprietary Current Mode Control Loop
  • Programmable CCM/DCM Operation
  • Programmable Phase Shift Control n 24-Lead (4mm × 4mm) QFN Package

Typical Application

LTC3874-1 Typical Application
LTC3874-1 Typical Application


The LTC®3874-1 is a dual PolyPhase® current mode synchronous step-down slave controller. It enables high current, multiphase applications when paired with a companion master controller by extending the phase count. Compatible master controllers include the LTC3884-1, LTC3774, LTC3875, LTC3877 and LTC3866. The LTC3874-1 employs a unique architecture that enhances the signal-to-noise ratio of the current sense signal, allowing the use of submilliohm 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 LTC3874-1 supports all the programmable features as well as fault protection.


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

Part Number Package Code Temp Package
LTC3874EUF-1#PBF 4x4 QFN-24 UF E 05-08-1697 Yes
LTC3874EUF-1#TRPBF 4x4 QFN-24 UF E 05-08-1697 Yes
LTC3874IUF-1#PBF 4x4 QFN-24 UF I 05-08-1697 Yes
LTC3874IUF-1#TRPBF 4x4 QFN-24 UF I 05-08-1697 Yes

LTC3874-1 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
LTC3874EUF-1#PBF 4x4 QFN-24 E $3.53 $2.47 Yes
LTC3874EUF-1#TRPBF 4x4 QFN-24 E $3.59 $2.53 Yes
LTC3874IUF-1#PBF 4x4 QFN-24 I $3.79 $2.65 Yes
LTC3874IUF-1#TRPBF 4x4 QFN-24 I $3.85 $2.71 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.

Click here to view our complete list of demo boards


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