LT3431 - High Voltage, 3A, 500kHz Step-Down Switching Regulator

The LT3431 is a 500kHz monolithic buck switching regulator that accepts input voltages up to 60V. A high efficiency 3A, 0.1 Ohm 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.

Features
  • 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: 0.1 Ohm
  • 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
Typical Application

Applications
  • Industrial and Automotive Power Supplies
  • Portable Computers
  • Battery Chargers
  • Distributed Power Systems
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT3431EFE#PBFTSSOP-16E$7.07$4.95
LT3431EFE#TRPBFTSSOP-16E$5.07
LT3431IFE#PBFTSSOP-16I$8.13$5.69
LT3431IFE#TRPBFTSSOP-16I$5.81
Demo Boards
Part NumberDescriptionPrice
DC549ALT3431EFE Demo Board | 60V Transients, 7.5V ≤ VIN ≤ 20V, Vout = 5V @ 2A$150.00
Datasheet
Design Note
Reliability Data
LTspice
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