LTC4251
RECOMMENDED FOR NEW DESIGNSNegative Voltage Hot Swap Controllers in SOT-23
- Part Models
- 13
- 1ku List Price
- Starting From $3.07
Overview
- Allows Safe Board Insertion and Removal from a Live –48V Backplane
- Floating Topology Permits Very High Voltage Operation
- Low Profile (1mm) ThinSOT™ Package
- Programmable Analog Current Limit with Circuit Breaker Timer
- Fast Response Time Limits Peak Fault Current
- Programmable Timer
- Programmable Undervoltage/Overvoltage Protection
The LTC4251/LTC4251-1/LTC4251-2 negative voltage Hot Swap™ controllers allow 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 feed forward path that limits peak current under worst-case catastrophic fault conditions.
Programmable undervoltage and overvoltage detectors disconnect the load whenever the input supply exceeds the desired operating range. The 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 LTC4251 UV/OV thresholds are designed to match the standard telecom operating range of –43V to –75V. The LTC4251-1 UV/OV thresholds extend the operating range to encompass –36V to –72V. The LTC4251-2 implements a UV threshold of –43V only.
| UV/OV | |
| LTC4251 | -43V / -75V |
| LTC4251-1 | -36V / -72V |
| LTC4251-2 | -43V UV Only |
| LTC4251B | -43V / -75V |
| LTC4251B-1 | -36V / -72V |
| LTC4251B-2 | -43V UV Only |
Applications
- Hot Board Insertion
- Electronic Circuit Breaker
- –48V Distributed Power Systems
- Negative Power Supply Control
- Central Office Switching
- Programmable Current Limiting Circuit
- High Availability Servers
- Disk Arrays
Documentation
Data Sheet 1
Technical Articles 1
Product Selector Card 1
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 Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC4251-1CS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251-1CS6#TRPBF | 6-Lead TSOT-23 | ||
| LTC4251-1IS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251-1IS6#TRPBF | 6-Lead TSOT-23 | ||
| LTC4251-2CS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251-2CS6#TRPBF | 6-Lead TSOT-23 | ||
| LTC4251-2IS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251-2IS6#TRPBF | 6-Lead TSOT-23 | ||
| LTC4251CS6#TRM | 6-Lead TSOT-23 | ||
| LTC4251CS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251CS6#TRPBF | 6-Lead TSOT-23 | ||
| LTC4251IS6#TRMPBF | 6-Lead TSOT-23 | ||
| LTC4251IS6#TRPBF | 6-Lead TSOT-23 |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
May 21, 2025 - 25_0033 Carsem SnPb Packaging End of Life |
||
| LTC4251CS6#TRM | ||
|
May 24, 2021 - 20_0074 Discontinuation of Sn/Pb Plated Lead Finish Parts for S5, S6, TS8 Packages |
||
| LTC4251CS6#TRM | ||
This is the most up-to-date revision of the Data Sheet.
Software Resources
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| Parts | Product Life Cycle | Description |
|---|---|---|
| Hot Swap Controllers 2 | ||
|
LTC4252 LTC4252A |
Negative Voltage Hot Swap Controllers | |
| LT4250 | RECOMMENDED FOR NEW DESIGNS | Negative 48V Hot Swap Controller |
Tools & Simulations
LTspice
Models for the following parts are available in LTspice:
- LTC4251
- LTC4251-1
- LTC4251-2
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.