Engineering Fail-Safe Power for Al Data Servers
Engineering Fail-Safe Power for AI Data Servers
Hot-swappable 48V power architectures are crucial for modern AI applications, especially in data centers—where continuous operation and the ability to handle high power loads are critical requirements.
Hot-Swap Circuit
This schematic illustrates a Hot-Swap Circuit, which allows electronic components to be safely inserted or removed from a live system without disrupting power or damaging components. Key elements include:
- Power Source: A dual-voltage input of +12V/48V, supplying the circuit.
- Low Ohmic Resistors (PMR Series): These resistors are placed near the power input to help manage inrush current and provide current sensing.
- Hot-Swap Controller: Central to the circuit, it regulates the power flow during insertion/removal events, ensuring safe operation.
- N-channel MOSFETs
- RY7P250BM (100V) and RS7E200BG (30V) are highlighted as new components.
- These MOSFETs act as switches controlled by the hot-swap controller to manage power delivery.
- 12V Controller IC (BD12780MUV-LB): Interfaces with the hot-swap controller to regulate voltage and provide system-level control.
- System Load: The final destination for regulated power, representing the operational electronics.
Source: ROHM Semiconductor
Conventional MOSFETs vs RY7P250BM
SOA Performance Comparison diagram showing current handling improvements of ROHM's DFN8080-8S package over TO-263AB at 48V and 25°C. DFN8080-8S supports 16A vs 1.8A at 10ms, and 50A vs 7.5A at 1ms pulse width.
This diagram compares the Safe Operating Area (SOA) performance of the conventional product TO-263AB to ROHM Semiconductor DFN8080-8S under these conditions:
- Drain-Source Voltage: VDS = 48V
- Ambient Temperature: Ta = 25°C
It evaluates performance at two pulse widths:
10ms Pulse Width
- TO-263AB (Conventional Product): SOA = 1.8A
- DFN8080-8S (New Product): SOA = 16A
- Improvement: ~8.8× higher current capacity
1ms Pulse Width
- TO-263AB: SOA = 7.5A
- DFN8080-8S: SOA = 50A
- Improvement: ~6.6× higher current capacity
The diagram visually emphasizes the superior current handling of the DFN8080-8S package, making it ideal for high-performance applications requiring robust thermal and electrical characteristics.
Source: ROHM Semiconductor
RY7P250BM Power MOSFET
Designed for high-reliability 48V applications
What sets it apart
Maximized uptime: Supports safe hot-swapping at full load without interrupting system operation
Ultra-low RDS(on) (1.86mΩ): Reduces conduction losses and improves thermal efficiency
±300A peak current rating: Handles demanding inrush currents and fast switching conditions
100VDSS rating: Suitable for 48V rails, offering ample transient protection headroom
DFN8080-8S package: Saves board space while providing direct thermal path via exposed drain pad
Why SOA matters in hot-swap design
Safe Operating Area (SOA) defines the voltage, current and time range a device can safely handle without damage. More SOA headroom translates to more robust, failure-resistant systems.
- Withstands high inrush and fault currents
- Minimizes thermal stress in power stages
- Enables safe, live module swaps
- Essential for hot-swapping in AI servers & data centers
- Wider SOA equates to greater reliability