LT1956 - High Voltage, 1.5A, 500kHz Step-Down Switching Regulators

The LT1956/LT1956-5 are 500kHz monolithic buck switching regulators with an input voltage capability up to 60V. A high efficiency 1.5A, 0.2 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 25µA and the device can be externally synchronized from 580kHz to 700kHz with a logic level input.

The LT1956/LT1956-5 are available in fused-lead 16-pin SSOP and thermally enhanced TSSOP packages.

Features
  • Wide Input Range: 5.5V to 60V
  • 1.5A Peak Switch Current
  • Small 16-Pin SSOP Package or Thermally Enhanced TSSOP Package
  • Saturating Switch Design: 0.2 Ohms
  • Peak Switch Current Maintained Over Full Duty Cycle Range
  • Constant 500kHz Switching Frequency
  • Effective Supply Current: 2.5mA
  • Shutdown Current: 25µA
  • 1.2V Feedback Reference (LT1956)
  • 5V Fixed Output (LT1956-5)
  • Easily Synchronizable
  • Cycle-by-Cycle Current Limiting
Typical Application

Applications
  • High Voltage, Industrial and Automotive
  • Portable Computers
  • Battery-Powered Systems
  • Battery Chargers
  • Distributed Power Systems
Packaging

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT1956EFE-5#PBFTSSOP-16E$5.36$3.75
LT1956EFE-5#TRPBFTSSOP-16E$3.87
LT1956EFE#PBFTSSOP-16E$5.36$3.75
LT1956EFE#TRPBFTSSOP-16E$3.87
LT1956EGN-5#PBFSSOP-16E$4.32$3.65
LT1956EGN-5#TRPBFSSOP-16E$3.71
LT1956EGN#PBFSSOP-16E$4.32$3.65
LT1956EGN#TRPBFSSOP-16E$3.71
LT1956IFE-5#PBFTSSOP-16I$6.36$4.45
LT1956IFE-5#TRPBFTSSOP-16I$4.57
LT1956IFE#PBFTSSOP-16I$6.36$4.45
LT1956IFE#TRPBFTSSOP-16I$4.57
LT1956IGN-5#PBFSSOP-16I$5.15$4.35
LT1956IGN-5#TRPBFSSOP-16I$4.41
LT1956IGN#PBFSSOP-16I$5.15$4.35
LT1956IGN#TRPBFSSOP-16I$4.41
Demo Boards
Part NumberDescriptionPrice
DC423BLT1956EFE | 1A, 500kHz High Voltage Buck Converter, Vin = 7V - 25V, Vout = 5V @ 1A$100.00
Datasheet
Design Note
Reliability Data
LT Journal
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