RS31388 - Stackable 4.5V to 16V, 50A eFuse with Current Monitoring

RS31388 – 4.5V to 16V, 55A Stackable eFuse with Current Monitoring

The RS31388 from Reed Semiconductor is a high-current, 55A stackable eFuse designed to provide reliable power-path protection, current monitoring, and controlled power distribution in demanding server, computing, and networking applications. Operating from a 4.5V to 16V input supply, the device integrates a low-resistance 0.6mΩ pass MOSFET to support efficient power delivery while minimizing conduction losses.

The RSM31388 supports up to 55A continuous current and 70A peak current. Multiple devices can be connected in parallel to support higher-current power rails, making the RSM31388 particularly suitable for scalable power distribution architectures.

With independently adjustable soft-start and steady-state current limits, programmable output soft-start timing, fast short-circuit protection, and integrated current monitoring, the RSM31388 combines flexible power management with robust fault protection in a compact 5mm × 5mm LGA-32 package.

High-Current 55A eFuse with Low-Loss Power Delivery

The RS31388 integrates a low-resistance 0.6mΩ pass MOSFET, enabling efficient power delivery in high-current systems where conduction losses and thermal performance are important design considerations.

Supporting an input voltage range of 4.5V to 16V, the device is well suited for protecting commonly used low-voltage power distribution rails, including 12V systems.

The RS31388 provides 55A continuous current capability with support for peak currents up to 70A. Its integrated power MOSFET eliminates the need for an external pass FET, reducing component count and simplifying the implementation of high-current power-path protection.

These characteristics make the device suitable for power-dense computing and networking platforms where reliable power distribution and compact PCB layouts are essential.

Parallel Operation for Scalable Power Distribution

A key feature of the RS31388 is its ability to operate with multiple devices connected in parallel, allowing designers to support power rails requiring higher current than a single device can provide.

This stackable architecture provides flexibility when developing scalable power distribution systems across different platform power requirements.

The device incorporates adjustable current-limit functionality and integrated current sensing to support current management during operation.

Parallel operation is particularly valuable in server and high-performance computing applications, where increasing processor and accelerator power requirements place greater demands on upstream power distribution networks.

By supporting multiple eFuses in parallel, the RS31388 provides a scalable approach to high-current power-path protection.

Independent Current Limits and Adjustable Soft-Start

The RS31388 provides independently adjustable current limits for soft-start and steady-state operation, allowing designers to configure protection behavior for different operating conditions.

During startup, the soft-start current limit helps manage the current delivered to downstream circuitry as the output voltage rises. During steady-state operation, a separately adjustable current limit provides protection against sustained overcurrent conditions.

An adjustable output soft-start timer provides additional control over startup timing, allowing the power path to be configured according to system requirements.

The device also includes an adjustable short-circuit current limit, providing further flexibility in defining protection thresholds.

These independent controls are particularly useful in applications with substantial downstream capacitance or varying load-current requirements.

Fast Short-Circuit Protection and Configurable Fault Response

The RS31388 integrates multiple protection functions designed to respond to abnormal operating conditions and help protect downstream components.

Fast-trip short-circuit protection provides rapid response to severe fault events, while an adjustable short-circuit current limit allows designers to configure the protection threshold.

The device also supports input-to-output short-circuit detection, providing additional fault-detection capability within the protected power path.

Selectable Latch-Off or Auto-Retry fault response allows the system to determine how the device responds following a protection event.

Latch-Off operation provides a shutdown response, while Auto-Retry supports automatic attempts to restore operation following a fault.

These configurable protection features allow the RS31388 to be adapted to different system-level fault-management requirements.

Accurate Current Monitoring and System Diagnostics

The RS31388 integrates accurate current-monitoring functionality, providing visibility into current flowing through the protected power path.

Current-monitoring information can support system diagnostics, load observation, and power-management functions in applications requiring monitoring of high-current distribution rails.

The device also provides fault indication and power-good indication outputs, allowing external system controllers to monitor operating status and respond to abnormal conditions.

These monitoring and status functions help simplify integration into systems requiring coordinated power sequencing, fault reporting, and power-path supervision.

Compact 5mm × 5mm LGA-32 Package

The RS31388 integrates its high-current pass MOSFET, protection circuitry, current monitoring, and control functions into a compact 5mm × 5mm, 32-pin LGA package.

The integrated architecture reduces external component requirements while supporting high-current power distribution in space-constrained designs.

The device is RoHS compliant and Green, supporting environmental compliance requirements for modern electronic equipment.

Applications for High-Current Power Protection

The RS31388 is designed for applications requiring reliable high-current power distribution, monitoring, and fault protection.

Typical applications include:

• Servers and High-Performance Computing: Protection of high-current power distribution rails supplying processors and other computing subsystems
• Graphics and Accelerator Cards: Controlled power delivery and fault protection for high-performance accelerator hardware
• Networking and Telecom Equipment: High-current power-path protection for communication infrastructure
• Storage Systems: Protected power distribution for storage controllers and associated electronics
• High-Current Power Distribution: Scalable protection using multiple eFuses connected in parallel

By combining 55A continuous current capability, 70A peak current support, a low-resistance integrated MOSFET, independent current-limit controls, and parallel operation, the RSM31388 provides a flexible solution for high-current power distribution and protection.

Explore Reed Semiconductor’s complete portfolio of eFuse and power-path protection solutions for additional devices supporting reliable, scalable power distribution.