RS31386 - Stackable 4.5V to 16V, 50A eFuse with Current Monitoring

RS31386 4.5V to 16V, 50A Scalable eFuse for High-Current Power Systems

Next-generation AI servers, GPU accelerators, networking equipment, and enterprise storage systems continue to demand increasing power while maintaining high reliability and robust fault protection. As power requirements grow beyond the capability of a single protection device, designers need a scalable solution that can expand current capacity without increasing design complexity.

The RS31386 is a fully integrated 50A stackable eFuse featuring a low 0.8mΩ power MOSFET, precision current monitoring, programmable protection, and active current sharing for high-current applications. Operating from 4.5V to 16V, the RS31386 is designed for standalone operation or as a companion device to the RS31380 intelligent PMBus eFuse, enabling scalable front-end power protection for applications requiring well beyond 50A.

By combining integrated protection, analog current monitoring, and seamless parallel operation, the RS31386 simplifies the design of high-current power architectures while reducing PCB area and component count.

---

Designed for Scalable High-Current Power Protection

The RS31386 enables designers to build power systems that can grow with increasing current requirements.

Typical applications include:

• AI accelerator cards
• GPU servers
• High-performance computing (HPC)
• Enterprise storage systems
• PCIe accelerator cards
• Networking switches
• Telecommunications equipment
• Server auxiliary power supplies
• Industrial computing platforms

Whether protecting a single 50A rail or supporting substantially higher current through multiple parallel devices, the RS31386 provides a flexible and scalable protection solution.

---

Standalone or Scalable Architecture

The RS31386 offers two deployment options.

Standalone Mode

The device operates as a complete 50A analog eFuse, providing:

• Adjustable current limiting
• Fast short-circuit protection
• Programmable soft start
• Accurate current monitoring
• Fault reporting
• Hot-swap capability

This makes it ideal for high-current analog power protection applications that do not require digital telemetry.

Companion Mode with the RS31380

For intelligent power systems, the RS31386 pairs directly with the RS31380 PMBus eFuse.

In this architecture:

• The RS31380 provides PMBus configuration, telemetry, and system-level control.
• One or more RS31386 devices increase the available output current while maintaining coordinated protection and active current sharing.

This modular approach allows designers to scale current capability while preserving a single intelligent control interface.

---

Low-Loss Integrated Power Path

The RS31386 integrates an ultra-low 0.8mΩ power MOSFET, minimizing conduction losses and improving efficiency compared to discrete controller and MOSFET solutions.

Benefits include:

• Lower power dissipation
• Reduced PCB area
• Simplified layout
• Lower BOM cost
• Improved thermal performance
• Higher power density

The integrated architecture also reduces design complexity and accelerates system qualification.

---

Comprehensive Analog Protection

The RS31386 integrates multiple protection mechanisms, including:

• Adjustable overcurrent protection
• Adjustable short-circuit current limit
• Fast-trip short-circuit protection
• Input-to-output short-circuit detection
• Input overvoltage protection
• Overtemperature protection
• Selectable latch-off or auto-retry fault response
• GOK and FLT_TYPE fault outputs

These programmable features allow designers to optimize system behavior for a wide range of high-power applications.

---

Accurate Current Monitoring

The integrated analog current monitor provides continuous visibility into system load current without requiring external current-sense amplifiers.

Current monitoring supports:

• Load diagnostics
• Power budgeting
• Thermal management
• Fault analysis
• Predictive maintenance

This analog interface provides a simple monitoring solution while complementing the digital telemetry available through the RS31380.

---

Built for AI and Data Center Power Systems

The RS31386 has been optimized for modern front-end power architectures requiring:

• High-current hot-swap capability
• Scalable power delivery
• Active current sharing
• Compact PCB layouts
• High efficiency
• Reliable fault protection

Its ability to operate independently or as part of a scalable intelligent power system makes it ideal for evolving server and accelerator platforms.

---

Seamlessly Expand the RS31380

When paired with the RS31380 intelligent eFuse, the RS31386 enables a modular approach to power scaling.

Rather than redesigning an entire protection stage, designers can simply add one or more RS31386 companion devices to increase available current while maintaining centralized PMBus control, telemetry, and coordinated protection. This scalable architecture simplifies qualification and accelerates development of next-generation high-power computing platforms.

---

Why Choose the RS31386?

The RS31386 combines a 50A integrated eFuse, 0.8mΩ power MOSFET, accurate current monitoring, and active current sharing into a compact, scalable solution for modern high-current power systems. Whether used as a standalone analog protection device or as a companion to the RS31380 intelligent PMBus eFuse, the RS31386 enables flexible, scalable power architectures for AI accelerators, servers, networking equipment, enterprise storage, and industrial computing.

---