LT3992 - Monolithic Dual Tracking 3A Step-Down Switching Regulator

Features

  • Wide Input Range:
    – Operation from 3V to 60V
  • Independent Supply, Shutdown, Soft-Start, UVLO, Programmable Current Limit and Programmable Power Good for Each 3A Regulator
  • Die Temperature Monitor
  • Adjustable/Synchronizable Fixed Frequency Operation from 250kHz to 2MHz with Synchronized Clock Output
  • Independent Synchronized Switching Frequencies Optimize Component Size
  • Antiphase Switching
  • Outputs Can Be Paralleled
  • Flexible Output Voltage Tracking
  • Low Dropout: 95% Maximum Duty Cycle
  • 5mm × 5mm QFN Package
  • FMEA Compliant 38-Pin Exposed Pad TSSOP Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT3992 Typical Application
LT3992 Typical Application

Description

The LT®3992 is a dual current mode PWM step-down DC/DC converter with two internal 4.6A switches. Independent input voltage, shutdown, feedback, soft-start, UVLO current limit and comparator pins for each channel simplify complex power supply tracking and sequencing requirements.

To optimize efficiency and component size, both converters have a programmable maximum current limit and are synchronized to either a common external clock input, or a resistor settable fixed 250kHz to 2MHz internal oscillator. A frequency divider is provided for channel 1 to further optimize component size. At all frequencies, a 180° phase relationship between channels is maintained, reducing voltage ripple and component size. A clock output is available for synchronizing multiple regulators.

Minimum input to output voltage ratios are improved by allowing the switch to stay on through multiple clock cycles only switching off when the boost capacitor needs recharging. Independent channel operation can be programmed using the SHDN pin. Disabling both converters reduces the total quiescent current to <10μA.

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
LT3992EFE#PBF TSSOP-38 FE E 05-08-1772 Yes
LT3992EFE#TRPBF TSSOP-38 FE E 05-08-1772 Yes
LT3992EUH#PBF 5x5 QFN-32 UH E 05-08-1693 Yes
LT3992EUH#TRPBF 5x5 QFN-32 UH E 05-08-1693 Yes
LT3992HFE#PBF TSSOP-38 FE H 05-08-1772 Yes
LT3992HFE#TRPBF TSSOP-38 FE H 05-08-1772 Yes
LT3992IFE#PBF TSSOP-38 FE I 05-08-1772 Yes
LT3992IFE#TRPBF TSSOP-38 FE I 05-08-1772 Yes
LT3992IUH#PBF 5x5 QFN-32 UH I 05-08-1693 Yes
LT3992IUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 Yes


LT3992 Package Drawing
LT3992 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
LT3992EFE#PBF TSSOP-38 E $7.22 $5.05 Yes
LT3992EFE#TRPBF TSSOP-38 E $5.11 Yes
LT3992EUH#PBF 5x5 QFN-32 E $6.64 $4.65 Yes
LT3992EUH#TRPBF 5x5 QFN-32 E $4.71 Yes
LT3992HFE#PBF TSSOP-38 H $8.30 $5.81 Yes
LT3992HFE#TRPBF TSSOP-38 H $5.87 Yes
LT3992IFE#PBF TSSOP-38 I $7.94 $5.56 Yes
LT3992IFE#TRPBF TSSOP-38 I $5.62 Yes
LT3992IUH#PBF 5x5 QFN-32 I $7.31 $5.12 Yes
LT3992IUH#TRPBF 5x5 QFN-32 I $5.18 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
DC1537A LT3992EFE Demo Board | Dual Buck with Tracking, 7V ≤ VIN ≤ 60V, Vout1 = 5V @ 2A, Vout2 = 3.3V @ 2A $225.00
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
LT3992HFE#PBF TSSOP-38 H $8.30 $5.81 Yes
LT3992HFE#TRPBF TSSOP-38 H $5.87 Yes
LT3992IFE#PBF TSSOP-38 I $7.94 $5.56 Yes
LT3992IFE#TRPBF TSSOP-38 I $5.62 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

  • Automotive Supplies
  • Distributed Supply Regulation

Product Notifications

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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:
LT3992

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

Design tools for the following parts are available in LTpowerCAD:
LT3992

Technical Support