Features and Benefits

  • Allows Safe Board Insertion and Removal from a Live –48V Backplane
  • Floating Topology Permits Very High Voltage Operation
  • Adjustable Analog Current Limit with Breaker Timer Ideal for Two Battery Feeds
  • Fast Response Time Limits Peak Fault Current
  • Three Sequenced Power Good Outputs
  • Improved Ruggedness Shunt Regulator
  • Adjustable Soft-Start Current Limit
  • Adjustable Timer with Drain Voltage Accelerated Response
  • Latchoff After Fault
  • Available in a 16-Pin SSOP Package

Product Details

The LTC4253B negative voltage Hot Swap controller allows a board to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current-limiting: a timed circuit breaker, active current limiting and a fast feedforward path that limits peak current under worst-case catastrophic fault conditions. The LTC4253B latches off after a circuit fault.

Adjustable undervoltage and overvoltage detectors disconnect the load whenever the input supply exceeds the desired operating range. The LTC4253B’s supply input is shunt-regulated, allowing safe operation with very high supply voltages. A multifunction timer delays initial start-up and controls the circuit breaker’s response time. The circuit breaker’s response time can be accelerated by sensing excessive MOSFET drain voltage, keeping the MOSFET within its safe operating area (SOA). An adjustable softstart circuit controls MOSFET inrush current at start-up.

Three power good outputs are sequenced by an adjustable timer and two ENABLE inputs to enable external power modules at start-up or disable them if the circuit breaker trips. The LTC4253B improves the ruggedness of the LTC4253 shunt regulator.

LTC4253A Recommend LTC4253B for new designs
LTC4253A-ADJ Recommend LTC4253B for new designs


  • –48V Distributed Power Systems
  • Negative Power Supply Control
  • Central Office Switching
  • High Availability Servers
  • Disk Arrays

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

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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.

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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.

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