LTC3852 - Low Input Voltage, Synchronous Step-Down DC/DC Controller

Features

  • Charge Pump Input Range: 2.7V to 5.5V
  • Controller Input Range: 4V to 38V
  • Integrated Charge Pump Provides 5V Gate Drive to Logic Level MOSFETs
  • RSENSE or DCR Current Sensing
  • ±1.25% Output Voltage Accuracy Over Temperature
  • Phase-Lockable Fixed Frequency: 250kHz to 750kHz
  • Power Good Output Voltage Monitor
  • Adjustable Soft-Start Voltage Ramping
  • Current Foldback Disabled During Start-Up
  • No Reverse Current During Soft-Start
  • Selectable Constant Frequency, Pulse-Skipping, or Burst Mode Operation
  • Output Overvoltage Protection
  • Very Low Dropout Operation: 99% Duty Cycle
  • Available in a 24-Lead (3mm x 5mm) QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3852 Typical Application
LTC3852 Typical Application

Description

The LTC3852 is a constant frequency, current mode step-down DC/DC controller which can be powered by an onboard charge pump. Input supplies as low as 2.7V, when doubled by the charge pump, provide 5V to the LTC3852’s control logic and gate drives, supporting a wide selection of logic-level N-channel power MOSFETs.

The constant-frequency current mode architecture allows for a phase-lockable fixed frequency of up to 750kHz. The RUN pin provides a precision enable threshold while the TRACK/SS pin combines tracking and adjustable soft-start features.

The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping mode, and continuous current mode. Current foldback limits MOSFET power dissipation during short-circuit conditions. Reverse current and current foldback functions are disabled during soft-start. A power good output pin indicates when the output is within ±10% of its designed set point.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

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

Part Number Package Code Temp Package
Drawing
RoHS
LTC3852EUDD#PBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3852EUDD#TRPBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3852IUDD#PBF 3x5 QFN-24 UDD I 05-08-1833 Yes
LTC3852IUDD#TRPBF 3x5 QFN-24 UDD I 05-08-1833 Yes


LTC3852 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
LTC3852EUDD#PBF 3x5 QFN-24 E $2.79 $1.95 Yes
LTC3852EUDD#TRPBF 3x5 QFN-24 E $2.01 Yes
LTC3852IUDD#PBF 3x5 QFN-24 I $3.29 $2.30 Yes
LTC3852IUDD#TRPBF 3x5 QFN-24 I $2.36 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
DC1270A LTC3852EUDD Demo Board | 2.7V ≤ VIN ≤ 5.5V, VOUT = 1.5V @ 15A Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

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
LTC3852IUDD#PBF 3x5 QFN-24 I $3.29 $2.30 Yes
LTC3852IUDD#TRPBF 3x5 QFN-24 I $2.36 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

  • General Purpose 3.3V Systems
  • Lithium-Ion Powered Devices
  • Distributed DC Power Systems

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LTC3852

Technical Support