Infineon Integrates Si, SiC, and GaN Technologies in New Power Supply Units
Included in the expanded PSU offerings is the "world's first 12 kW power supply unit."
In-Depth Analysis of Infineon’s 8-kW AI Power Supply Unit
The 8-kW PSU solution from Infineon adopts a hybrid switching approach, integrating three different types of semiconductors: silicon carbide (SiC), gallium nitride (GaN), and silicon. Each material is selected to optimize overall performance.
- **Silicon Carbide (SiC):** Utilized in the bridgeless totem-pole power factor correction (PFC) circuit due to its lower temperature coefficient of RDS(on). This choice enhances efficiency at elevated temperatures.
- **Gallium Nitride (GaN):** Employed in the high-frequency full-bridge resonant converter (LLC) owing to its lower capacitances, which facilitate higher switching frequencies and improve power density.
- **Silicon:** Incorporated in areas where switching losses are minimal, providing low RDS(on) for improved performance.
Functional blocks of the 8-kW PSU solution.
Key Components
The PSU incorporates several advanced components to ensure high performance and safety:
- **CoolSiC MOSFETs (650 V)**
- **CoolGaN Transistors (650 V)**
- **CoolMOS 8 SJ MOSFETs (600 V)**
- **CoolSiC Schottky Diodes (650 V)**
- **OptiMOS 5 Power MOSFETs (80 V)**
- **Digital Isolators (ISOFACE)**
- **EiceDRIVER Components**
These components collectively contribute to the PSU's high efficiency, performance, and safety.
Efficiency
Achieving an impressive efficiency of 98%, Infineon’s 8-kW PSU reduces cooling demands and enhances overall system reliability. It offers a high power density of 100 W/in³, which is double the ORv3 specification, making it ideal for modern AI rack infrastructures due to its compact form factor. Designed to operate with a single-phase high-line grid input ranging from 180 VAC to 305 VAC, the PSU delivers a nominal output of 50 VDC. It can supply up to 160 A, providing a maximum output power of 8 kW, sufficient to meet the high demands of AI applications.
Power Management
The unit features full digital control for both the interleaved bridgeless totem-pole PFC and the full-bridge LLC, enhancing precision and flexibility in power management to ensure optimal performance under varying load conditions. The proprietary and integrated magnetics design further optimizes the PSU's efficiency and performance. To meet stringent hold-up time requirements while maintaining high power density, the PSU incorporates an auxiliary boost circuit. This circuit leverages intermediate energy storage, reduces reliance on bulky capacitors, and enhances system reliability.
Addressing AI Concerns
With AI workloads consuming an increasing share of data center resources, there is a growing need for power supplies that are both highly efficient and robust. Infineon’s new range of AI PSUs uses a hybrid switching approach that combines the advantages of silicon, SiC, and GaN technologies in a single device. This innovative solution scales with the expanding energy demands of AI applications, enabling data centers to adapt to future requirements while maintaining energy efficiency and minimizing environmental impact.
All images used courtesy of Infineon.
