AI Server Power (48V → 12V → POL)
AI Server Power – High-Reliability & Ultra-High Current Magnetics for 48V AI
Modern AI servers utilize a multi-stage 48V power architecture to handle extreme GPU/CPU power demands. This page highlights how Coilmaster’s SEP1005A, SBP, and SEP-EX series optimize the 48V-to-POL power chain, offering superior high-voltage insulation, transient stability, and ultra-low DCR for next-generation computing racks.
As AI workloads drive rack power density to 100kW and beyond, the transition to 48V distribution is mandatory to minimize I²R losses. However, the 48V stage requires magnetics that can withstand higher voltage stress and continuous high-current loads without compromising long-term reliability.
This AI Server Power page details the selection logic for the entire power chain—from 48V intermediate bus conversion (IBC) to sub-1V Point-of-Load (POL) stages. We focus on specialized structures like Assembled Shielded Inductors and Ultra-low DCR VRM Inductors to ensure maximum efficiency and electrical safety in modern AI data centers.
Why 48V Architecture is the Standard for AI
The move to 48V Power Delivery (PD) is driven by the physical limits of current and heat in high-performance computing.
- 94% Reduction in Distribution Loss: Moving from 12V to 48V reduces the current by 4x, resulting in a 16x reduction in distribution losses.
- Support for Multi-kW GPU Clusters: Enables stable power delivery to ultra-dense OAM (OCP Accelerator Module) and UBB (Universal Baseboard) configurations.
- Enhanced Electrical Safety: Our specialized inductors are designed to handle 48V bus transients while maintaining strict insulation integrity.
Power Conversion Stages: Where Magnetics Matter
Each stage of the AI power chain requires a specific magnetic philosophy to balance efficiency and reliability:
1. 48V to 12V Intermediate Bus Converter (IBC)
This stage handles the high-voltage drop from the rack bus. It requires inductors with high insulation strength and superior thermal stability, such as the SEP1005A series.
2. Multi-Phase VRMs for GPU/CPU Core Power
The final Point-of-Load (POL) stage requires inductors with Ultra-Low DCR and fast transient response (high di/dt) to maintain a stable sub-1V supply during rapid AI workload shifts.
3. Isolated Auxiliary Power & Sensing
Providing isolated rails for management controllers (BMC) and precise current monitoring via EE5.0 series for system-level power telemetry.
Selection Logic for AI Server Magnetics
For high-density computing, magnetics selection must prioritize electrical integrity alongside efficiency:
- High-Voltage Insulation Reliability: In 48V stages, assembled shielded structures reduce the risk of wire insulation damage compared to molded types, ensuring safer long-term operation.
- di/dt Transient Stability: Inductors must maintain a predictable inductance slope during rapid GPU load steps to prevent voltage undershoot.
- Thermal Predictability: Components must hold stable saturation characteristics across +25°C to 125°C to prevent system crashes during peak compute cycles.
Featured Magnetics Solutions for AI Servers
Coilmaster provides a specialized portfolio for the 48V-to-POL power chain:
1. 48V Intermediate Bus – SEP1005A & SEP-EX Series
For the critical 48V stage, the SEP1005A Assembled Shielded Series offers superior high-voltage endurance and lower risk of insulation failure. Together with the SEP-EX Flat-Wire Series, they provide the robust current handling and efficiency required for high-density IBC modules.
2. GPU / CPU Core Power – SBP Series
Our flagship SBP Series VRM inductors feature ultra-low DCR and stable saturation performance up to 125°C, optimized for the high di/dt requirements of modern GPU cores.
3. Isolated Power & Sensing – PE & EE5.0 Series
The PE Series Planar Transformers deliver high power density for isolated conversion, while the EE5.0 Series provides compact current sensing for real-time power monitoring.
Engineering Support & Modeling
We help AI hardware teams optimize their power maps through:
- Inductance stability review at 100°C+ operating temperatures for SBP/SEP-EX series.
- Insulation and reliability assessment for SEP1005A in 48V architectures.
- Custom footprint tuning for height-constrained OCP-compliant designs.
Related FAQ
Why are VRM inductors critical for GPUs and CPUs?
They directly control current ripple and voltage stability during fast compute load changes.
Why does 48V architecture improve AI server efficiency?
It reduces distribution loss and allows higher rack-level power density.
Why is DCR so important in POL inductors?
At hundreds of amps, even small resistance creates large losses and heat.
- Related Products
3.3uH, 8A Flat wire power inductor
SEP0605A-3R3M-LF
State-of-the-art SMD Flat Wire Power Inductor, a compact marvel engineered to elevate your designs to new heights. With dimensions of just 7.0x6.9x5.0,...
Details Add to List10uH, 7.6A Surface Mount Flat Wire High Efficiency Inductors
SEP6060EX-100M-LF
Surface Mount Flat Wire Molded Inductor, SEP6060EX series (6.1mm height), which offers high current handling capacity, low DC resistance and low power...
Details Add to List0.12uH, 102A multiphase buck converter tlvr inductor
SBP110511Q-R12L-LF
0.12uH, 102A SMD TLVR power inductor, in the ever-evolving landscape of data centers, storage systems, graphics cards, and personal computing devices,...
Details Add to List- Related FAQ
Why do AI servers need multiple power stages?
To efficiently convert 48V distribution to low-voltage, high-current rails.
Why are flat-wire inductors used in VRMs?
They provide low DCR and high current capability.
What EMI challenges exist in AI servers?
Fast switching and dense layouts create noise that can affect signal integrity.