LTC3871 - Bidirectional PolyPhase® Synchronous Buck or Boost Controller
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Typical Application

LTC3871 Typical Application
LTC3871 Typical Application


The LTC®3871 is a high performance bidirectional buck or boost switching regulator controller that operates in either buck or boost mode on demand. It regulates in buck mode from VHIGH-to-VLOW and boost mode from VLOW-to-VHIGH depending on a control signal, making it ideal for 48V/12V automotive dual battery systems. An accurate current programming loop regulates the maximum current that can be delivered in either direction. The LTC3871 allows both batteries to supply energy to the load simultaneously by converting energy from one battery to the other.

Its proprietary constant-frequency current mode architecture enhances the signal-to-noise ratio enabling low noise operation and provides excellent current matching between phases. Additional features include discontinuous or continuous mode of operation, OV/UV monitors, independent loop compensation for buck and boost operation, accurate output current monitoring and overcurrent protection.


7mm x 7mm LQFP-48

LTC3871 Package Drawing
Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price
LTC3871HLXE#PBF LQFP 48 H $9.74 $6.82
LTC3871ELXE#PBF LQFP 48 E $7.71 $5.40
LTC3871ILXE#PBF LQFP 48 I $9.22 $6.45
* 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
DC2348A-A LTC3871HLXE#PBF Demo Board | Bidirectional Controller, Buck Mode: 30V ≤ VIN ≤ 75V, VOUT = 12V @ 60A; Boost Mode: 10V ≤ VIN ≤ 13V, VOUT = 48V @ 15A $400.00
DC2348A-B LTC3871HLXE#PBF Demo Board | Bidirectional Controller, Buck Mode: 30V ≤ VIN ≤ 75V, VOUT = 12V @ 30A; Boost Mode: 10V ≤ VIN ≤ 13V, VOUT = 48V @ 7.5A $300.00