LTC3864 - 60V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability

Features

  • Wide Operating VIN Range: 3.5V to 60V
  • Wide VOUT Range: 0.8V to VIN
  • Low Operating IQ = 40μA
  • Very Low Dropout Operation: 100% Duty Cycle
  • Strong High Voltage MOSFET Gate Driver
  • Constant Frequency Current Mode Architecture
  • Verified FMEA for Adjacent Pin Open/Short
  • Selectable High Efficiency Burst Mode® Operation or Pulse-Skipping Mode at Light Loads
  • Programmable Fixed Frequency: 50kHz to 850kHz
  • Phase-Lockable Frequency: 75kHz to 750kHz
  • Accurate Current Limit
  • Programmable Soft-Start or Voltage Tracking
  • Internal Soft-Start Guarantees Smooth Start-Up
  • Power Good Output Voltage Monitor
  • Low Shutdown IQ = 7μA
  • Available in Small 12-Pin Thermally Enhanced MSOP and DFN Packages
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC3864 Typical Application
LTC3864 Typical Application

Description

The LTC®3864 is a robust, high voltage step-down DC/DC controller optimized for automotive and industrial applications. It drives a P-channel power MOSFET switch allowing 100% duty cycle operation. The wide input and output voltage ranges cover a multitude of applications. This device has been verified with the failure mode and effects analysis (FMEA) procedure for operation during failure conditions.

The LTC3864 offers excellent light load efficiency, drawing only 40μA quiescent current in a user programmable Burst Mode operation. Its peak current mode, constant frequency PWM architecture provides for good control of switching frequency and output current limit. The switching frequency can be programmed from 50kHz to 850kHz with an external resistor and can be synchronized to an external clock from 75kHz to 750kHz.

The LTC3864 offers programmable soft-start or output tracking. Safety features include overvoltage protection, overcurrent and short-circuit protection including frequency foldback and a power good output signal.

The LTC3864 is available in thermally enhanced 12-Pin MSOP and 3mm × 4mm DFN packages.

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
LTC3864EDE#PBF 4x3 DFN-12 DE/UE E 05-08-1695 Yes
LTC3864EDE#TRPBF 4x3 DFN-12 DE/UE E 05-08-1695 Yes
LTC3864EMSE#PBF MS-12E MSE E 05-08-1666 Yes
LTC3864EMSE#TRPBF MS-12E MSE E 05-08-1666 Yes
LTC3864HDE#PBF 4x3 DFN-12 DE/UE H 05-08-1695 Yes
LTC3864HDE#TRPBF 4x3 DFN-12 DE/UE H 05-08-1695 Yes
LTC3864HMSE#PBF MS-12E MSE H 05-08-1666 Yes
LTC3864HMSE#TRPBF MS-12E MSE H 05-08-1666 Yes
LTC3864IDE#PBF 4x3 DFN-12 DE/UE I 05-08-1695 Yes
LTC3864IDE#TRPBF 4x3 DFN-12 DE/UE I 05-08-1695 Yes
LTC3864IMSE#PBF MS-12E MSE I 05-08-1666 Yes
LTC3864IMSE#TRPBF MS-12E MSE I 05-08-1666 Yes
LTC3864MPDE#PBF 4x3 DFN-12 DE/UE MP 05-08-1695 Yes
LTC3864MPDE#TRPBF 4x3 DFN-12 DE/UE MP 05-08-1695 Yes
LTC3864MPMSE#PBF MS-12E MSE MP 05-08-1666 Yes
LTC3864MPMSE#TRPBF MS-12E MSE MP 05-08-1666 Yes


LTC3864 Package Drawing
LTC3864 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
LTC3864EDE#PBF 4x3 DFN-12 E $2.94 $2.06 Yes
LTC3864EDE#TRPBF 4x3 DFN-12 E $2.12 Yes
LTC3864EMSE#PBF MS-12E E $2.94 $2.06 Yes
LTC3864EMSE#TRPBF MS-12E E $2.12 Yes
LTC3864HDE#PBF 4x3 DFN-12 H $3.90 $2.73 Yes
LTC3864HDE#TRPBF 4x3 DFN-12 H $2.79 Yes
LTC3864HMSE#PBF MS-12E H $3.90 $2.73 Yes
LTC3864HMSE#TRPBF MS-12E H $2.79 Yes
LTC3864IDE#PBF 4x3 DFN-12 I $3.49 $2.44 Yes
LTC3864IDE#TRPBF 4x3 DFN-12 I $2.50 Yes
LTC3864IMSE#PBF MS-12E I $3.49 $2.44 Yes
LTC3864IMSE#TRPBF MS-12E I $2.50 Yes
LTC3864MPDE#PBF 4x3 DFN-12 MP $9.40 $6.58 Yes
LTC3864MPDE#TRPBF 4x3 DFN-12 MP $6.64 Yes
LTC3864MPMSE#PBF MS-12E MP $9.40 $6.58 Yes
LTC3864MPMSE#TRPBF MS-12E MP $6.64 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
DC1722A LTC3864EMSE Demo Board | 5.5V ≤ VIN ≤ 55V; VOUT = 5V @ 2A $100.00
DC2434A LTC3864 Demo Board | Buck Controller, 12V ≤ VIN ≤ 60V, Vout = 12V @ 5A Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data 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
LTC3864HDE#PBF 4x3 DFN-12 H $3.90 $2.73 Yes
LTC3864HDE#TRPBF 4x3 DFN-12 H $2.79 Yes
LTC3864HMSE#PBF MS-12E H $3.90 $2.73 Yes
LTC3864HMSE#TRPBF MS-12E H $2.79 Yes
LTC3864IDE#PBF 4x3 DFN-12 I $3.49 $2.44 Yes
LTC3864IDE#TRPBF 4x3 DFN-12 I $2.50 Yes
LTC3864IMSE#PBF MS-12E I $3.49 $2.44 Yes
LTC3864IMSE#TRPBF MS-12E I $2.50 Yes
LTC3864MPDE#PBF 4x3 DFN-12 MP $9.40 $6.58 Yes
LTC3864MPDE#TRPBF 4x3 DFN-12 MP $6.64 Yes
LTC3864MPMSE#PBF MS-12E MP $9.40 $6.58 Yes
LTC3864MPMSE#TRPBF MS-12E MP $6.64 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

  • Industrial and Automotive Power Supplies
  • Telecom Power Supplies
  • Distributed 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:

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

Models for the following parts are available in LTspice:
LTC3864

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

To open the project file for this circuit:

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

Design tools for the following parts are available in LTpowerCAD:
LTC3864

Technical Support