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
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.
- Industrial and Automotive Power Supplies
- Portable Computers
- Battery Chargers
- Distributed Power Systems
Product Lifecycle 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)
Demonstration circuit 549 is a monolithic step-down DC/DC switching converter using the LT3431. The board is optimized for 5V output at up to 2A load current for a steady state input voltage range of 7.5V to 20V. The LT3431 is capable of withstanding input transients to 60V and runs at 500kHz with steady state input voltages that require duty cycles between 25% and 75%.
Tools & Simulations
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.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
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.
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.