Overview
Features and Benefits
- 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
Product Details
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.
Retry / Latch Off | Features | Package | |
LT4256-1 | Latch Off | UV | SO-8 |
LT4256-2 | Retry | UV | SO-8 |
LT4256-3 | Latch Off or Retry | UV/OV, Open Circuit Detect | SSOP-16 |
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
Product Categories
Product Lifecycle
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.
Evaluation Kits (1)
Documentation & Resources
-
R568 Reliability Data3/23/2018
-
DC684A - Demo Manual1/6/2014
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Hot Swap Controllers8/2/2023
Tools & Simulations
LTspice
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.

Models for the following parts are available in LTspice:
Product Recommendations
LT4256-3 Companion Parts
Recommended Related Parts
Design Resources
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.View our quality and reliability program and certifications for more information.
Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
---|---|---|---|---|
LT4256-3CGN#PBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LT4256-3CGN#TRPBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LT4256-3IGN#PBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LT4256-3IGN#TRPBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
Wafer Fabrication Data | R568 Reliability Data |
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Support & Discussions
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.