With the exponential growth of AI chip performance, server power consumption has surged. For example, Nvidia’s B200 GPU consumes 1000W per chip, and the GB200 model reaches 2700W, pushing server rack power demand from 20kW to over 120kW. Traditional 12V power systems struggle with high power transmission due to increased I²R losses, rising thermal costs, and limited scalability from bulky wiring. As a result, data centers are shifting to higher voltage power systems.
Along with the upgrade to a 48V power bus, significant changes have also been seen in the implementation of hot-swap technology. This article explores the evolution of the 48V power architecture, the role of hot-swap technology, and the latest innovations in this field.
Adopting a 48V system offers several advantages, including:
A 48V system reduces the current by four times compared to a 12V system, leading to a 16-fold reduction in transmission losses, thereby significantly improving energy efficiency. For instance, while a 12V system would require 1000A to transmit 12kW of power, a 48V system only requires 250A. When paired with optimized bus designs, overall efficiency can increase by 10%-15%.
The 48V architecture supports smaller wires and components, reducing the space occupied by the wiring harness. Additionally, vertical power flow designs—such as placing VRM modules under chips—shorten current paths, further lowering losses and increasing power density.
The 48V system is compatible with existing infrastructure (such as 48V backup battery systems) and lays the foundation for future transitions to even higher voltages, such as ±400V. The modular design (e.g., PRM pre-regulation modules + VTM voltage conversion modules) enables flexible adaptation to various computational needs, supporting different conversion ratios such as 5:1 or 8:1.
To achieve high power density in 48V systems, innovations in power management focus on efficient conversion, intelligent monitoring, and advanced materials. ZSC Zero Voltage Switching supports >1MHz soft switching to minimize losses, while HSC Hybrid Switching Capacitor technology enhances efficiency for high step-down ratios. Real-time monitoring of voltage, current, and temperature, combined with predictive algorithms, optimizes energy distribution and fault prevention. In case of power loss, a BBU with supercapacitors ensures response within 10ms for uninterrupted operation.
Material and packaging advancements further improve system performance. Wide-bandgap semiconductors like GaN and SiC increase switching speed and voltage tolerance, while flip-chip packaging enhances thermal efficiency and reliability. These innovations collectively drive the evolution of 48V architectures, meeting the growing power demands of AI servers.
In AI servers, hot-swap technology is crucial for ensuring system continuity and high availability, minimizing downtime. It allows for component replacement without shutting down the system, avoiding total shutdowns.
However, hot-swap processes present several challenges. One significant issue is surge currents. When inserting components, the input capacitors charge rapidly, causing surge currents that can peak up to 4.3kA, potentially damaging equipment or causing voltage drops.
In such cases, MOSFETs are used as current controllers, adjusting the gate voltage (V_GS) to limit the current. By referencing the Safe Operating Area (SOA) curve, the MOSFET ensures safe operation at high voltages (e.g., 60V). The controller dynamically adjusts the current based on the MOSFET’s SOA curve to prevent overheating or breakdown.
Infineon has expanded its XDP digital protection product series with the XDP711-001, a digital hot-swap controller designed specifically for high-power AI servers with a 48V wide input voltage range. This controller features programmable SOA control and precise input/output voltage monitoring with accuracy as low as ≤0.4%. It also monitors system input current with a precision of ≤0.75% across the entire ADC range, improving fault detection and reporting accuracy.
The XDP711-001 employs pulse SOA current control technology, ensuring safer startups even in systems without optimal FETs, thus reducing BOM costs. It supports driving multiple parallel MOSFETs, which is essential for high-power designs required by AI servers. The controller's three-block architecture integrates high-precision telemetry for fault detection, optimized digital SOA control for power MOSFETs, and high-current integrated drivers capable of handling up to 8 N-channel power MOSFETs.
The transition to a ±400V DC architecture is accelerating, enabling data centers to handle 500kW+ per rack with greater efficiency. Liquid cooling is emerging as a key solution, significantly improving thermal management and reducing PUE by over 30%. Meanwhile, AI-driven power optimization dynamically adjusts energy distribution, predicts load fluctuations, and enhances system reliability, paving the way for smarter and more efficient data center operations.
In conclusion, the advancements in 48V power architectures and hot-swap technology are essential to addressing the rising power demands of AI servers. These innovations ensure that data centers can meet the performance needs of next-generation AI applications while improving energy efficiency, system reliability, and scalability
