RS31312

RS31312 15A eFuse with Hot-Swap Protection and Current Monitoring

Modern servers, networking equipment, communications systems, and industrial electronics depend on reliable 12V auxiliary power rails to supply storage devices, PCIe cards, optical modules, and embedded subsystems. The RS31312 is a highly integrated 15A eFuse that provides intelligent hot-swap protection, programmable fault management, and accurate current monitoring, helping designers protect valuable downstream circuitry while simplifying power system design.

Designed for 4.5V to 16V distributed power rails, the RS31312 integrates a low 2.7mΩ pass MOSFET, adjustable current limiting, configurable input overvoltage protection, programmable soft-start, and comprehensive fault protection into a compact 3 × 5 mm QFN-22 package. By combining power-path protection, hot-swap control, and system monitoring into a single IC, the RS31312 reduces component count while improving overall system reliability.

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Optimized for 12V Auxiliary Power Distribution

As power systems become increasingly complex, protecting auxiliary power rails is just as important as protecting high-current processor supplies. The RS31312 is optimized for 12V and intermediate voltage buses, making it an excellent choice for protecting loads that require controlled startup and robust fault handling.

Typical applications include:

• Server auxiliary power rails
• PCI and PCIe expansion cards
• Networking switches and routers
• Optical modules
• Industrial automation equipment
• Embedded computing systems
• Digital television and multimedia equipment

Its wide 4.5V to 16V operating range provides flexibility across a broad range of distributed power architectures.

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Intelligent Hot-Swap Protection

Hot-plug events and large output capacitance can generate damaging inrush currents. The RS31312 incorporates programmable startup control that allows designers to safely power downstream loads while minimizing electrical stress.

Integrated features include:

• Adjustable current limit
• Programmable soft-start
• Programmable hot-plug insertion delay
• Adjustable fault blanking timer
• Fast short-circuit protection (<200 ns typical)
• Integrated overtemperature protection

These features help eliminate nuisance trips while providing fast protection against genuine fault conditions.

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Low-Loss High-Current Power Delivery

The integrated 2.7mΩ pass MOSFET minimizes conduction losses and thermal dissipation while supporting up to 15A continuous load current.

Benefits include:

• Reduced voltage drop
• Improved system efficiency
• Lower thermal stress
• Smaller PCB footprint
• Reduced external component count

This combination of low on-resistance and high current capability makes the RS31312 well suited for high-density computing and communications equipment.

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Advanced Protection and System Control

Beyond basic overcurrent protection, the RS31312 includes several advanced features that improve overall system robustness.

Integrated capabilities include:

• Configurable input overvoltage protection
• Accurate analog current monitor output
• Load Enable (LOADEN) input
• Programmable LOADEN blanking time
• Fault output
• Power-good indication
• Input-to-output short-circuit detection

These features provide designers with greater flexibility when implementing power sequencing, fault handling, and system supervision.

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Simplify High-Reliability Power Designs

The RS31312 replaces numerous discrete components—including a power MOSFET, hot-swap controller, current-sense circuitry, and protection logic—with a single integrated solution.

Compared with discrete implementations, the RS31312 helps designers:

• Reduce PCB area
• Lower BOM cost
• Improve system reliability
• Simplify layout
• Shorten development time

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Part of Reed Semiconductor’s eFuse Portfolio

The RS31312 complements Reed Semiconductor’s expanding family of intelligent eFuses, providing designers with protection solutions optimized for different voltage and current requirements.

This portfolio enables designers to choose the optimal protection device based on voltage, current, monitoring, and system integration requirements.

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Why Choose the RS31312?

The RS31312 combines 15A current capability, low-loss power delivery, intelligent hot-swap protection, and advanced system monitoring into a compact, highly integrated solution for 4.5V to 16V power rails. With programmable startup timing, configurable overvoltage protection, accurate current monitoring, and comprehensive fault management, it helps designers build more reliable servers, networking equipment, industrial systems, and embedded platforms while reducing component count and simplifying power system design.