LTC3856
RECOMMENDED FOR NEW DESIGNS2-Phase Synchronous Step-Down DC/DC Controller with Diffamp
- Part Models
- 8
- 1ku List Price
- Starting From $4.82
Overview
- 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
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.
Applications
- Telecom and Datacom Systems
- Industrial and Medical Instruments
- DC Power Distribution Systems
- Computer Systems
Documentation
Data Sheet 1
User Guide 1
Application Note 1
Design Note 1
Technical Articles 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3856EFE#PBF | 38-Lead TSSOP w/ EP | ||
| LTC3856EFE#TRPBF | 38-Lead TSSOP w/ EP | ||
| LTC3856EUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3856EUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3856IFE#PBF | 38-Lead TSSOP w/ EP | ||
| LTC3856IFE#TRPBF | 38-Lead TSSOP w/ EP | ||
| LTC3856IUH#PBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) | ||
| LTC3856IUH#TRPBF | 32-Lead QFN (5mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
May 18, 2026 - 26_0072 Epoxy Change for Select TSSOP Products |
||
| LTC3856EFE#PBF | PRODUCTION | |
| LTC3856EFE#TRPBF | PRODUCTION | |
| LTC3856IFE#PBF | PRODUCTION | |
| LTC3856IFE#TRPBF | PRODUCTION | |
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LTC3856EFE#PBF | PRODUCTION | |
| LTC3856EFE#TRPBF | PRODUCTION | |
| LTC3856IFE#PBF | PRODUCTION | |
| LTC3856IFE#TRPBF | PRODUCTION | |
|
Jan 20, 2022 - 21_0269 Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products |
||
| LTC3856EUH#PBF | PRODUCTION | |
| LTC3856EUH#TRPBF | PRODUCTION | |
| LTC3856IUH#PBF | PRODUCTION | |
| LTC3856IUH#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3856
LTpowerCAD 2
- LTC3856 Project - 2-Phase Synchronous Step-Down Supply with Inductor DCR Current Sensing (4.5-14V to 1.5 @ 50A)
- LTC3856 Project - 2-Phase Synchronous Step-Down Supply with Rsense Current Sensing (4.5-14V to 1.5 @ 50A)
Design tools for the following parts are available in LTpowerCAD:
- LTC3856
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Evaluation Kits
LTC3856EUH Demo Board | 4.5V ≤ VIN ≤ 14V, VOUT = 1.5V @ 50A
Resources
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