LT3692A - Monolithic Dual Tracking 3.5A Step-Down Switching Regulator

Features

  • Wide Input Range:
    – Operation from 3V to 36V
    – OVLO Protects Circuit Through 60V Transients
  • Independent Supply, Shutdown, Soft-Start, UVLO, Programmable Current Limit and Programmable Power Good for Each 3.5A Regulator
  • Die Temperature Monitor
  • Adjustable/Synchronizable Fixed Frequency Operation from 250kHz to 2.25MHz 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 data available for specific packages


Typical Application

LT3692A Typical Application
LT3692A Typical Application
LT3692A Typical Application

Description

The LT®3692A is a dual current mode PWM step-down DC/DC converter with two internal 3.8A 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 2.25MHz 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.

The LT3692A is an improved version of the LT3692 with reduced minimum on-time.

  Min On-Time Features Package
LT3692 180ns - 5x5 QFN-32
LT3692A 140ns Programmable Shutdown UVLO TSSOP-38E, 5x5 QFN-32

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
LT3692AEFE#PBF TSSOP-38 FE E 05-08-1772 Yes
LT3692AEFE#TRPBF TSSOP-38 FE E 05-08-1772 Yes
LT3692AEUH#PBF 5x5 QFN-32 UH E 05-08-1693 Yes
LT3692AEUH#TRPBF 5x5 QFN-32 UH E 05-08-1693 Yes
LT3692AHFE#PBF TSSOP-38 FE H 05-08-1772 Yes
LT3692AHFE#TRPBF TSSOP-38 FE H 05-08-1772 Yes
LT3692AHUH#PBF 5x5 QFN-32 UH H 05-08-1693 Yes
LT3692AHUH#TRPBF 5x5 QFN-32 UH H 05-08-1693 Yes
LT3692AIFE#PBF TSSOP-38 FE I 05-08-1772 Yes
LT3692AIFE#TRPBF TSSOP-38 FE I 05-08-1772 Yes
LT3692AIUH#PBF 5x5 QFN-32 UH I 05-08-1693 Yes
LT3692AIUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 Yes


LT3692A Package Drawing
LT3692A 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
LT3692AEFE#PBF TSSOP-38 E $6.64 $4.65 Yes
LT3692AEFE#TRPBF TSSOP-38 E $4.71 Yes
LT3692AEUH#PBF 5x5 QFN-32 E $6.07 $4.25 Yes
LT3692AEUH#TRPBF 5x5 QFN-32 E $4.31 Yes
LT3692AHFE#PBF TSSOP-38 H $7.67 $5.37 Yes
LT3692AHFE#TRPBF TSSOP-38 H $5.43 Yes
LT3692AHUH#PBF 5x5 QFN-32 H $7.07 $4.95 Yes
LT3692AHUH#TRPBF 5x5 QFN-32 H $5.01 Yes
LT3692AIFE#PBF TSSOP-38 I $7.31 $5.12 Yes
LT3692AIFE#TRPBF TSSOP-38 I $5.18 Yes
LT3692AIUH#PBF 5x5 QFN-32 I $6.71 $4.70 Yes
LT3692AIUH#TRPBF 5x5 QFN-32 I $4.76 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
DC1403A LT3692A Demo Board I 7V to 36V Input, Vout1 = 5V @ 3A, Vout2 = 3.3V @ 3A $225.00
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
LT3692AHFE#PBF TSSOP-38 H $7.67 $5.37 Yes
LT3692AHFE#TRPBF TSSOP-38 H $5.43 Yes
LT3692AHUH#PBF 5x5 QFN-32 H $7.07 $4.95 Yes
LT3692AHUH#TRPBF 5x5 QFN-32 H $5.01 Yes
LT3692AIFE#PBF TSSOP-38 I $7.31 $5.12 Yes
LT3692AIFE#TRPBF TSSOP-38 I $5.18 Yes
LT3692AIUH#PBF 5x5 QFN-32 I $6.71 $4.70 Yes
LT3692AIUH#TRPBF 5x5 QFN-32 I $4.76 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

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Design Tools

LTspiceIV

LTspice® IV 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 IV

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 IV
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice IV 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 IV:
LT3692
LT3692A

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:
LT3692A

Technical Support