LTC3853 - Triple Output, Multiphase Synchronous Step-Down Controller

Features

  • Triple, 120° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
  • Configurable as a 180° Dual Phase Controller Plus a Single Phase Controller
  • The Third Phase Can Regulate Up to a 13.5V Output
  • High Efficiency: Up to 92%
  • RSENSE or DCR Current Sensing
  • ±0.75% 0.8V Output Voltage Accuracy
  • Phase-Lockable Fixed Frequency 250kHz to 750kHz
  • Supports Pre-Biased Outputs
  • Dual N-Channel MOSFET Synchronous Drive
  • Wide VIN Range: 4.5V to 24V Operation (28V Abs Max)
  • Adjustable Soft-Start Current Ramping or Tracking
  • Foldback Output Current Limiting
  • Output Overvoltage Protection
  • Dual Power Good Output Voltage Monitors
  • 40-Lead 6mm × 6mm QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3853 Typical Application

Description

The LTC®3853 is a high performance triple output stepdown switching regulator controller that drives all Nchannel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents.

A wide 4.5V to 24V (28V maximum) input voltage supply range encompasses most battery chemistries and intermediate bus voltages. Phase 3 can regulate output voltages up to 13.5V. A constant-frequency current mode architecture allows for a phase-lockable frequency up to 750kHz.

Independent TK/SS pins for each output ramps the output voltages and can be configured for coincident or ratiometric tracking. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping or continuous inductor current modes.

Packaging

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

Part Number Package Code Temp Package
Drawing
RoHS
LTC3853EUJ#PBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3853EUJ#TRPBF 6x6 QFN-40 UJ E 05-08-1728 Yes
LTC3853HUJ#PBF 6x6 QFN-40 UJ H 05-08-1728 Yes
LTC3853HUJ#TRPBF 6x6 QFN-40 UJ H 05-08-1728 Yes
LTC3853IUJ#PBF 6x6 QFN-40 UJ I 05-08-1728 Yes
LTC3853IUJ#TRPBF 6x6 QFN-40 UJ I 05-08-1728 Yes
LTC3853MPUJ#PBF 6x6 QFN-40 UJ MP 05-08-1728 Yes
LTC3853MPUJ#TRPBF 6x6 QFN-40 UJ MP 05-08-1728 Yes


LTC3853 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
(1-99)
Price
(1k)*
RoHS
LTC3853EUJ#PBF 6x6 QFN-40 E $5.04 $3.53 Yes
LTC3853EUJ#TRPBF 6x6 QFN-40 E $3.59 Yes
LTC3853HUJ#PBF 6x6 QFN-40 H $6.06 $4.24 Yes
LTC3853HUJ#TRPBF 6x6 QFN-40 H $4.30 Yes
LTC3853IUJ#PBF 6x6 QFN-40 I $5.63 $3.94 Yes
LTC3853IUJ#TRPBF 6x6 QFN-40 I $4.00 Yes
LTC3853MPUJ#PBF 6x6 QFN-40 MP $15.22 $10.65 Yes
LTC3853MPUJ#TRPBF 6x6 QFN-40 MP $10.71 Yes
Buy NowRequest Samples
* 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
DC1254A LT3853EUJ Demo Board | Triple, PolyPhase, 6.5V ≤ VIN ≤ 24V, Vout1 = 2.5V/5A, Vout2 = 1.8V/5A, Vout3 = 3.3V/5A $250.00
DC1349A LTC3853EUJ Demo Board | Triple, PolyPhase, 6.5V ≤ VIN ≤ 14V, Vout1 = 1.8V/15A, Vout2 = 1.2V/15A, Vout3 = 2.5V/15A $250.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Appications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3853HUJ#PBF 6x6 QFN-40 H $6.06 $4.24 Yes
LTC3853HUJ#TRPBF 6x6 QFN-40 H $4.30 Yes
LTC3853IUJ#PBF 6x6 QFN-40 I $5.63 $3.94 Yes
LTC3853IUJ#TRPBF 6x6 QFN-40 I $4.00 Yes
LTC3853MPUJ#PBF 6x6 QFN-40 MP $15.22 $10.65 Yes
LTC3853MPUJ#TRPBF 6x6 QFN-40 MP $10.71 Yes
Buy NowRequest Samples
* 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.

Applications

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LTC3853

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