LT4256-3 - Positive High Voltage Hot Swap Controller with Open-Circuit Detect

The LT4256-3 is a high voltage Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. An internal driver controls the high side N-channel MOSFET gate for supply voltages ranging from 10.8V to 80V. The part features an open-circuit detect (OPEN) output that indicates abnormally low load current conditions.

The LT4256-3 also features an adjustable analog foldback current limit. If the supply remains in current limit for more than a programmable time, the N-channel MOSFET shuts off, the PWRGD output asserts low and the LT4256-3 either automatically restarts after a time-out delay or latches off until the UV pin is cycled low (depending on the status of the RETRY pin).

The PWRGD output indicates when the output voltage rises above a programmed level. An external resistor string from VCC provides programmable undervoltage and overvoltage protection.

The LT4256-3 is available in a 16-lead SSOP package.

Features
  • Allows Safe Board Insertion and Removal from a Live Backplane
  • Controls Supply Voltage from 10.8V to 80V
  • Foldback Current Limiting
  • Open Circuit and Overcurrent Fault Detect
  • Drives an External N-Channel MOSFET
  • Automatic Retry or Latched Off Operation After Overcurrent Fault
  • Programmable Supply Voltage Power-Up Rate
  • Open MOSFET Detection
  • 1% Over and Undervoltage Detection Accuracy
  • Available in a 16-Lead SSOP Package
Typical Application

Applications
  • Hot Board Insertion
  • Electronic Circuit Breaker/Power Bussing
  • Industrial High Side Switch/Circuit Breaker
  • 24V/48V Industrial/Alarm Systems
  • Ideally Suited for 12V, 24V and 48V Distributed Power Systems
  • 48V Telecom Systems
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT4256-3CGN#PBFSSOP-16C$2.95$2.10
LT4256-3CGN#TRPBFSSOP-16C$2.16
LT4256-3IGN#PBFSSOP-16I$3.48$2.45
LT4256-3IGN#TRPBFSSOP-16I$2.51
Demo Boards
Part NumberDescriptionPrice
DC684ALT4256-3 Positive Voltage Hot Swap Controller$75.00
Datasheet
Reliability Data
Product Selector Card
Related Product
LT4256-3 - Positive High Voltage Hot Swap Controller with Open-Circuit Detect
R568 - Reliability Data
Hot Swap Controllers
LT4256-3 Footprints and Symbols