Webinar: Benefits & Advantages of GaN in a Data Center PSU
In This Webinar You’ll Learn:
- The Economic and Sustainability value of GaN in Power Supply Units
- GaN’s technical advantages in Power Factor Correction and LLC Resonant Converter topologies
- How to take advantage of GaN Systems’ Next Generation Power Stages in 3 key areas:
- Thermal Performance
- Switching Performance
- Efficiency Improvement
Questions & Answers
I’m not a server power supply designer. What is "Titanium" rating?
Data Center PSUs get tested to industry standard performance requirements. One of the criteria is efficiency. A 94% efficiency at 50% load is named Platinum. A 96% measured efficiency at 50% load is call Titanium. The industry has shifted to requiring Titanium or even Titanium plus efficiency levels, meaning higher then 96% efficiency at 50% load.
Though top cool is more affordable could CerStrateTM be more economical if power loss and manufacturability is factored into over cost?
Absolutely, this is one of the advantages of the CerStrate Power Stage design. The cost adder of the CerStrate power stage PCB is minor when considering the total system BOM cost. When considering the system cost, CerStrate can actually help to reduce the total BOM cost when things such as heatsink size, and manufacturability are taken into account.
Do you need to bias the GaN FETs gate negatively in the mentioned topology?
Negative gate bias is not required but can be implemented depending on factors such as layout, dV/dt, power level and desired design margin. Generally we recommend a 2-3 volt negative gate bias voltage for turn off for hard-switched topologies in the 3kW range to eliminate any risk of false turn-on. Refer to our Application Note GN012 for specific recommendations.
Where are these products placed on the Open Compute Program. Are they certified, and would it soon become part of the standard pack. Whats your view on this?
We are seeing designs with GaN in the power shelf power supplies and in the Battery Backup Unit (BBU). We cannot comment on certification, that is the responsibility of the system manufacturer.
Have you faced any issues with meeting the 20 ms hold up time. the peak current capabilities are lower. Can you comment ?
We do not see any issues with the 20ms hold-up time requirement. The power switch is not usually the bottleneck. Using GS66508B as an example, the peak current capability is 60A, which is sufficient for 3kW data center applications.
I’ve done PFC circuits before and can achieve close to the same efficiency as you mentioned. Why do we need to consider using Gallium Nitride?
GaN not only provides a much lower switching loss but also enables the use of the totem pole PFC topology, which has better magnetic and semiconductor utilization. GaN provides a significant advantage for increasing the power density of the power converter along with increasing efficiency.
Should I consider interleaving topologies for data Center PSU?
Interleaving is a great method to reach higher power and higher power density for power converters. The interleaved two-phase topology can cancel each other’s noise and current ripple to reduce the EMI filter and magnetics components size. However, there is a bit of a cost premium for interleaving drivers, aux power supplies, and a more powerful controller. So, there is a trade-off, and the decision is case by case depending on design objectives.
Should I choose CRM or CCM control for the PFC stage?
Although CRM control can achieve ZVS to reduce switching loss and hard switching noise, when the power is higher than 1kW, the peak current for CRM will be somewhat challenging to handle. So, in general, CCM is preferred.
I am interested in evaluating the reference designs for the PFC and LLC. How do I get them? Are the IMS boards available also?
Yes, visit our website for our 3kW PFC and LLC reference designs. The IMS boards are also available on our website. You can review details on the “Evaluation Kits & Reference Designs” section in “Design Center” pulldown area of our website. You can purchase them from our distributors.
Do you offer design support for the transformer and other passives?
Yes, we offer comprehensive engineering support to our customers for transformer design and passives selection. Please contact your local sales representative for more information.
Moderator: Paul Wiener
VP Strategic Marketing at GaN Systems
Paul Wiener is GaN Systems’ Vice President of Strategic Marketing. Prior to joining GaN Systems, Paul led the power magnetics business unit at Eaton. Paul brings more than 25 years’ experience in operations, sales and marketing, and business development. His experience includes vice president of sales at Fultec Semiconductor Inc. and several management roles at Genoa, BroadLogic, and Raychem.
