Application of MOSFET in server power supply

Infineon / Mitsubishi / Fuji / Semikron / Eupec / IXYS

Application of MOSFET in server power supply

Posted Date: 2024-01-26

1. Introduction to server power supply

Server power supplies are mainly used in data center scenarios, and are mainly used in servers, storage and other equipment. Like PC power supply, it is a switching power supply.

Server power supplies can be divided into two types: ATX power supplies and SSI power supplies according to standards.

The ATX standard is a specification launched by Intel in 1997. It is widely used. The output power is generally between 125 watts and 350 watts. It is mainly used in desktop computers, workstations and low-end servers. The SSI (Server System Infrastructure) specification is a new server power supply specification launched by Intel and some major IA architecture server manufacturers. The SSI specification was developed to standardize server power supply technology, reduce development costs, and extend the service life of servers. It is mainly Including server power supply specifications, backplane system specifications, server chassis system specifications and cooling system specifications.

Currently, most data center operators use 12V DC input as the mainboard power supply. In a traditional architecture, an uninterruptible power supply (UPS) would provide backup power to two independent AC distribution schemes throughout the data center. In a typical server motherboard, two AC-DC power supplies provide redundancy with each other, with each power supply being sufficient to meet the entire power needs of the server motherboard.

2. Server power supply market analysis

AI and ChatGPT applications are booming. In addition to the core computing chips, power supplies are also one of the focus topics of market discussion.

At present, the power of some server power supplies on the market has exceeded 3000W. Some manufacturers predict that the power supply of AI servers in the future will reach 5000W or even 8000W.

According to IDC data, the global TOP5 server manufacturers have a high market concentration, basically maintaining 50%. The main players are Dell, HPE, Inspur, Lenovo and SuperMicro. It is expected that global server shipments will reach 14.407 million units by 2025, with China reaching 14.407 million units. 4.162 million units, accounting for 29% of the world. The global server power supply market will reach 31.6 billion yuan in 2025, with a CAGR of 11% from 2020 to 2025. The Chinese market will reach 9.1 billion yuan, with a CAGR of 11% from 2020 to 2025.

3. Server power topology and Longteng product advantages

Usually titanium-grade high-efficiency power supplies consist of a bridgeless or semi-bridgeless PFC stage (such as a totem pole stage) and a resonant DC-DC stage (such as an LLC converter) (see the figure below). Most 12V output voltages use center-tapped transformers, while 48V systems should consider full-bridge rectification.

Totem pole PFC+LLC topology

Totem pole PFC+LLC topology: the first-level PFC circuit. When the circuit starts, the inrush current is large, requiring the MOSFET to have strong EAS capability. The high-frequency bridge arm requires the MOS to have good switching performance, and the low-frequency bridge arm requires the MOS to have small conduction. ;The downstream LLC resonant circuit requires the MOSFET's Body Diode to have strong di/dt capability and small Qrr.

For server power market applications, Longteng Semiconductor's high-voltage SJ MOS has product advantages:

For PFC topology, optimize EAS to enhance avalanche resistance and surge resistance;

For LLC topology, optimize the body diode, enhance di/dt capability, and reduce Qrr and drive interference;

Optimize Qg and Coss/Ciss ratio to reduce drive loss and improve drive anti-interference capability.

Server power supply market application, Longteng Semiconductor's SGT MOS, its product advantages:

Optimize Qg and Vth, high and consistent Vth makes parallel connection safer and more reliable;

Optimize Coss and Rdson to reduce switching loss and conduction loss to a greater extent and reduce temperature rise.

The above advantages make the application of Longteng products in server power supply simple.

4. Server power supply Longteng MOSFET selection table

Function Topology Product Series Product number AD-DC PFC 600-700V SJ MOS 650VIGBT LSB65R070GT LSB65R099GT LKB40N65TM1 ​​Isolated DC-DC (primary) PSFB LLC DAB LSB65R070GF LSB65R099GF LSC65R135GF Isolated DC-DC (secondary) Synchronous rectification 12V Vout 40-60V SGT MOS LSGN04R011WE LSGN04R013WE Synchronous rectification 24V Vout 80 -100V SGT MOS LSGN08R036 LSGE08R036 LSGN10R042 synchronous rectifier
48V Vout 150V
SGT MOS under development

Note: The above information and data come from Longteng Semiconductor

Review Editor: Liu Qing

#Application #MOSFET #server #power #supply