RS31512
Stackable 20A eFuse with PMBus Digital Telemetry
Features
Protection & Reliability
• The RS31512 supports a wide 9V to 80V operating input voltage
• Integrated ultra-low 4.3mΩ power MOSFET
• 20A continuous and 24A peak output current capability
• Independent startup and steady-state current limit control
• Adjustable short-circuit current limit
• Fast short-circuit protection
• Selectable latch-off or auto-retry protection
• Input-to-output short-circuit detection
PMBus & System Management
• PMBus interface for configuration and telemetry
• Integrated precision current monitoring
• Fault indication and power-good indication
Scalability & Control
• Standalone or leader operation in parallel applications
• Adjustable output soft-start time
• Parallel operation for higher-current applications
Package & Compliance
• Compact 5mm × 6mm LGA-24 package
• RoHS compliant
Description
RS31512 60A Stackable PMBus eFuse for 48V AI Power Distribution
Intelligent Protection for the 48V Backbone of AI Power
The RS31512 is a 9V to 80V stackable 60A eFuse with integrated PMBus digital configuration and telemetry, optimized to protect 48V power distribution rails in AI servers, accelerators, networking equipment, storage systems, and high-performance computing platforms. Featuring an integrated 4.3mΩ MOSFET, 60A continuous and 80A peak current capability, configurable protection thresholds, precision current monitoring, and comprehensive fault protection, the RS31512 safeguards high-power distribution rails while minimizing power loss.
Designed for placement between the 48V distribution bus and the intermediate bus converter (IBC), the RS31512 protects one of the most critical power paths in modern AI power architectures. Its stackable architecture allows multiple devices to operate in parallel, enabling scalable current capability while maintaining coordinated protection, PMBus configuration, and telemetry.
Optimized for 48V Front-End Protection
Modern AI servers distribute power using a 48V architecture to reduce distribution losses and improve system efficiency. The 48V bus feeds one or more intermediate bus converters (IBCs), which generate lower-voltage rails for downstream multiphase voltage regulators powering GPUs, CPUs, and AI accelerators.
The RS31512 is specifically optimized to protect this front-end power rail by providing:
- Controlled inrush current limiting for large IBC input capacitors
- Independent startup and steady-state current-limit control
- Adjustable short-circuit current limiting
- Fast short-circuit protection
- Input overvoltage protection
- Overtemperature protection
- Selectable latch-off or auto-retry operation
Its wide 9V to 80V operating range also makes it suitable for telecom, industrial, and distributed power applications.
Independent Startup and Operating Current Protection
Unlike conventional eFuses that use a single current limit for all operating conditions, the RS31512 independently programs startup and steady-state current limits.
This enables designers to:
- Optimize inrush current during startup.
- Maximize available operating current.
- Reduce nuisance trips caused by charging large IBC input capacitors.
- Improve overall system reliability during transient loading.
This independent current-limit architecture is particularly valuable in AI power systems, where intermediate bus converters present large capacitive loads during startup.
PMBus Configuration and Real-Time Telemetry
The integrated PMBus interface enables remote configuration and real-time telemetry for intelligent power management.
Key capabilities include:
- Digital configuration of protection thresholds
- Precision current monitoring
- Fault reporting and diagnostics
- Power-good indication
- System health monitoring
These features simplify system diagnostics, improve serviceability, and enable predictive maintenance in AI, cloud, and enterprise computing platforms.
Scale Beyond 60A
As AI accelerators continue to increase power consumption, front-end protection must scale with system requirements.
The RS31512 supports 60A continuous and 80A peak current per device, while multiple devices can be connected in parallel to support even higher-current 48V distribution rails.
This scalable architecture enables a common protection platform to support a broad range of AI server power levels while simplifying hardware development and inventory management.
Protect the Entire AI Power Architecture
The RS31512 is optimized for protecting the 48V distribution rail ahead of the intermediate bus converter (IBC).
For protecting downstream intermediate bus and point-of-load (POL) rails, Reed Semiconductor offers a comprehensive portfolio of scalable analog and PMBus-enabled eFuses optimized for lower-voltage, higher-current applications.
Together, Reed’s eFuse portfolio provides intelligent protection from the 48V input bus all the way to the processor power rails.
Designed for AI Infrastructure
The RS31512 is ideal for protecting 48V power distribution rails in:
- AI servers
- GPU and AI accelerator platforms
- High-performance computing (HPC)
- Cloud infrastructure
- Networking switches and routers
- Storage systems
- Telecom equipment
- Industrial computing platforms
Applications
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- Graphics and accelerator cards
- Servers and high-performance computing
