RS31511 - Stackable 80V, 20A eFuse

RS31511 Stackable 20A eFuse for 48V Power Distribution and Hot-Swap Protection

Modern AI servers, networking equipment, storage platforms, telecommunications infrastructure, and industrial computing systems require intelligent protection for high-power DC distribution rails. The RS31511 is a 9V to 80V, 20A stackable eFuse with an integrated 3.6mΩ power MOSFET that protects high-current power rails from overcurrent, short-circuit, overvoltage, and overtemperature faults while providing accurate current monitoring and controlled startup.

Designed for 48V power distribution architectures, the RS31511 is ideal for protecting intermediate bus converters (IBCs), power shelves, accelerator cards, and other high-power loads where reliable fault protection and controlled inrush current are essential. By integrating the protection circuitry and power MOSFET into a single device, the RS31511 simplifies system design, reduces board space, and improves overall system reliability compared to discrete protection solutions.

Optimized for 48V AI and Data Center Power Systems

As AI processors continue to increase in power consumption, protecting the 48V distribution rail has become increasingly important. A fault on a high-current rail can damage expensive downstream power converters, processors, or system infrastructure while causing costly downtime.

The RS31511 provides comprehensive protection for these applications by combining:

• Programmable current limiting
• Fast-trip short-circuit protection
• Input overvoltage protection
• Overtemperature protection
• Controlled startup and inrush current limiting
• Precision analog current monitoring

These capabilities help maximize system uptime while protecting valuable downstream circuitry during startup, overload conditions, and fault events.

The device is particularly well suited for placement ahead of intermediate bus converters (IBCs), where it protects the converter and downstream multiphase voltage regulators from abnormal operating conditions.

Standalone Protection That Scales with Your System

One of the key advantages of the RS31511 is its flexible architecture.

A single RS31511 supports 20A continuous and 24A peak output current, making it suitable for many standalone applications. As system power requirements increase, multiple RS31511 devices can be connected in parallel to provide higher current capability while maintaining coordinated operation and active current sharing.

This scalable architecture allows designers to develop a common hardware platform that can be easily adapted to different power levels simply by increasing the number of parallel devices. The result is reduced design effort, simplified qualification, and a lower overall system cost.

Adjustable Protection for Improved System Reliability

Every power system has unique startup and operating requirements. The RS31511 allows designers to optimize protection by independently configuring the startup and steady-state current limits.

Additional programmable features include:

• Output soft-start time
• Short-circuit current threshold
• Fast-trip threshold
• Overcurrent blanking time
• Selectable latch-off or auto-retry protection mode

This flexibility allows the RS31511 to accommodate capacitive loads, high inrush current applications, and demanding system startup sequences while minimizing nuisance shutdowns.

Analog Current Monitoring

The integrated current monitor provides an analog output proportional to the load current, allowing the host system to monitor power consumption without requiring additional sensing circuitry.

Combined with the device’s Power Good and fault indication outputs, designers can quickly identify abnormal operating conditions, monitor system loading, and improve overall system diagnostics.

Because the RS31511 uses an analog interface, it can be easily integrated into existing power architectures without the complexity of a digital communication bus.

Ideal Applications

The RS31511 is designed for a wide range of high-reliability power systems, including:

• AI servers and accelerator platforms
• GPU and PCIe accelerator cards
• Intermediate bus converter (IBC) protection
• Server power distribution
• Networking switches and routers
• Storage systems
• Telecommunications infrastructure
• Industrial computing equipment
• High-power embedded systems

Need PMBus Configuration and Telemetry?

The RS31511 provides the simplicity and reliability of an analog eFuse while delivering accurate current monitoring and comprehensive fault protection.

For applications requiring PMBus digital configuration, telemetry, and diagnostics, Reed Semiconductor offers the RS31512, a PMBus-enabled companion device built on the same scalable protection architecture. Optimized for the same 48V power distribution applications, the RS31512 adds intelligent system monitoring and remote configuration while supporting the same scalable parallel operation concept.

See more eFuse solutions from Reed here.