1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. High Input Voltage Buck Regulators
  6. LT3431


Overview

Features and Benefits

  • Wide Input Range: 5.5V to 60V
  • 3A Peak Switch Current
  • Small Thermally Enhanced 16-Pin TSSOP Package
  • Constant 500kHz Switching Frequency
  • Saturating Switch Design: 0.1Ω
  • Peak Switch Current Maintained Over Full Duty Cycle Range
  • Effective Supply Current: 2.5mA
  • Shutdown Current: 30µA
  • 1.2V Feedback Reference Voltage
  • Easily Synchronizable
  • Cycle-by-Cycle Current Limiting

Product Details

The LT3431 is a 500kHz monolithic buck switching regulator that accepts input voltages up to 60V. A high efficiency 3A, 0.1Ω switch is included on the die along with all the necessary oscillator, control and logic circuitry. A current mode architecture provides fast transient response and good loop stability.

Special design techniques and a new high voltage process achieve high efficiency over a wide input range. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. Patented circuitry maintains peak switch current over the full duty cycle range. A shutdown pin reduces supply current to 30µA and the device can be externally synchronized from 580kHz to 700kHz with logic level inputs.

The LT3431 is available in a thermally enhanced 16-pin TSSOP package.

Applications

  • Industrial and Automotive Power Supplies
  • Portable Computers
  • Battery Chargers
  • Distributed Power Systems

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

Tools & Simulations

LTspice

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, 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.

LTspice

Models for the following parts are available in LTspice:

LT3431

Product Recommendations

LT3431 Companion Parts

Recommended Related Parts

Recommended Suggested Oscillator

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
LT3431EFE#PBF Material Declaration Reliability Data 16-Lead TSSOP w/ EP
LT3431EFE#TRPBF Material Declaration Reliability Data 16-Lead TSSOP w/ EP
LT3431IFE#PBF Material Declaration Reliability Data 16-Lead TSSOP w/ EP
LT3431IFE#TRPBF Material Declaration Reliability Data 16-Lead TSSOP w/ EP
Wafer Fabrication Data R468 Reliability Data

PCN-PDN Information

Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.

Sample & Buy


Ordering FAQs


See our Ordering FAQs for answers to questions about online orders, payment options and more.

 

Buy Now Pricing


(**) Displayed Buy Now Price and Price Range is based on small quantity orders.

 

List Pricing


(*)The 1Ku 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 Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

 

Lead Times


Please see the latest communication from our CCO regarding lead times.

 

Sampling


A Sample link will be shown above, next to the part, only for parts that are included in our sample program. Selecting the Sample button will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.


Price Table Help

 

Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.