Power Management Switching Regulator Step-Down (Buck) Regulators Poly-Phase Buck Controllers
Power Management Switching Regulator Step-Down (Buck) Regulators External Power Switch Buck Controllers

LTC2974 - 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement

LTC3880 - Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

LTC3856 - 2-Phase Synchronous Step-Down DC/DC Controller with Diffamp

Features

  • PolyPhase® Controller Reduces Input and Output Capacitance and Power Supply Induced Noise
  • Wide VIN Range: 4.5V to 38V Operation
  • ±0.75%, 0.6V Reference Voltage Accuracy
  • High Efficiency: Up to 95%
  • Programmable Burst Mode® Operation or Stage Shedding™ for Highest Light Load Efficiency
  • Active Voltage Positioning (AVP)
  • RSENSE or DCR Current Sensing
  • Programmable DCR Temperature Compensation
  • Phase-Lockable Fixed Frequency: 250kHz to 770kHz
  • True Remote Sense Differential Amplifier
  • Dual N-Channel MOSFET Synchronous Drive
  • VOUT Range: 0.6V to 5V without Differential Amplifier
  • VOUT Range: 0.6V to 3.3V with Differential Amplifier
  • Adjustable Soft-Start or VOUT Tracking
  • Stackable for Up to 12-Phase Operation
  • 32-Pin (5mm × 5mm) QFN and 38-Pin TSSOP Packages

Typical Application

LTC3856 Typical Application
LTC3856 Typical Application

Description

The LTC3856 is a single output, dual channel PolyPhase synchronous step-down DC/DC controller that drives all N-channel power MOSFET stages. This device includes a high speed differential amplifier for remote output voltage sense. Power loss and supply noise are minimized by operating the two controller output stages out-of-phase and up to 12-phase operation can be achieved.

The LTC3856 monitors the output current by sensing the voltage drop across the output inductor (DCR) or by using a sense resistor. DCR temperature compensation maintains an accurate current sense threshold over a broad temperature range. A constant-frequency, current mode architecture allows a phase-lockable frequency of up to 770kHz.

A wide 4.5V to 38V input supply range encompasses most intermediate bus voltages and battery chemistries. Burst Mode operation, continuous or Stage Shedding modes are supported. A TK/SS pin shared by both channels ramps the output voltage during start-up.

Packaging

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

QFN-32, TSSOP-38

LTC3856 Package Drawing
LTC3856 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC3856EFE#PBF TSSOP 38 E $4.96 $3.47 View
LTC3856EFE#TRPBF TSSOP 38 E $3.53 View
LTC3856EUH#PBF QFN 32 E $4.54 $3.18 View
LTC3856EUH#TRPBF QFN 32 E $3.24 View
LTC3856IFE#PBF TSSOP 38 I $5.46 $3.82 View
LTC3856IFE#TRPBF TSSOP 38 I $3.88 View
LTC3856IUH#PBF QFN 32 I $5.22 $3.65 View
LTC3856IUH#TRPBF QFN 32 I $3.71 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.

Part Number Description Price Documentation
DC1580A LTC3856EUH Demo Board | PolyPhase, Synchronous Reg Contact Factory
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Applications

  • Telecom and Datacom Systems
  • Industrial and Medical Instruments
  • DC Power Distribution Systems
  • Computer Systems

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Related models available in LTspice IV
LTC3856

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