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GaN / PRODUCT & TECHNOLOGY / WBG3 Min Read
Transphorm, Inc. announced it has demonstrated up to 5 microsecond short circuit withstand time (SCWT) on a GaN power transistor with a patented technology. The achievement is the first of its kind on record, marking an important milestone for the industry as a whole. It proves Transphorm GaN’s ability to meet the required short circuit capabilities of rugged power inverters such as servo motors, industrial motors, and automotive powertrains served traditionally by silicon IGBTs or silicon carbide (SiC) MOSFETs— an over $3 billion GaN TAM over the next 5 years.
The demonstration was developed with support from Yaskawa Electric Corporation, a long-term strategic partner of Transphorm’s and a global leader in low and medium voltage drives, servo systems, machine controllers, and industrial robots. This makes GaN a highly attractive power conversion technology for servo systems, as it allows for higher efficiency and reduced size compared to incumbent solutions.
To do that, GaN must pass stringent robustness tests—of which, short-circuit survivability is the most challenging. In case of short-circuit faults, the device must survive extreme conditions with both high current and high voltage. The system can take up to a few microseconds to detect the fault and shut down the operations. During this time, the device must withstand the fault on its own.
“If a power semiconductor device cannot survive short-circuit events, the system itself may fail. There was a strong perception that GaN power transistors could not meet the short circuit requirements needed for heavy-duty power applications such as ours,” said Motoshige Maeda, Department Manager of Fundamental R&D Management Department, Corporate Technology Division, Yaskawa. “Having worked with Transphorm for many years, we believed that perception to be unfounded and have been proven right today. We’re excited about what their team has accomplished and look forward to demonstrating how this new GaN feature can benefit our designs.”
The short-circuit technology has been demonstrated on a newly designed 15 mΩ 650 V GaN device. Notably, that device reaches a peak efficiency of 99.2% and a maximum power of 12 kW in hard-switching conditions at 50 kHz. The device demonstrated not only performance, but also reliability, passing high-temperature high-voltage stress requirements.
“Standard GaN devices can withstand short-circuit for only a few hundredths of nanoseconds, which is too short for fault detection and safe shut-down. However, with our cascode architecture and key patented technology, we were able to demonstrate short-circuit withstand time up to 5 microseconds with no additional external components, thus retaining low cost and high performance,” said Umesh Mishra, CTO and Co-Founder, Transphorm.
“We understand the demands of high-power, high-performance inverter systems. We have a long history of strong innovation, and we’re proud to say that experience helped us bring GaN to the next level. This is yet another validation of Transphorm’s global leadership in high voltage GaN robustness and reliability and will be a gamechanger for GaN in motor drives and other high-power systems.”
The full description explaining the SCWT achievement, the demonstration analysis, and more is expected to be presented at a major power electronics conference next year.
Original – Transphorm
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GaN / LATEST NEWS / WBG3 Min Read
Navitas Semiconductor announced that its CRPS185 3,200 W “Titanium Plus” server reference design not only surpasses the stringent 80Plus Titanium efficiency requirements, but also effectively satisfies the increasing power demands of AI data center power.
The rapid development and deployment of artificial intelligence (AI) including OpenAI’s ChatGPT, Microsoft’s Bing with AI, and Google’s Bard, has penetrated all aspects of people’s lives. New power-hungry AI processors like NVIDIA’s DGX GH200 ‘Grace Hopper’ demand up to 1,600 W each, are driving power-per-rack specifications from 30-40 kW up to 100 kW per cabinet. Meanwhile, with the global focus on energy conservation and emission reduction, as well as the latest European regulations, server power supplies must exceed the 80Plus ‘Titanium’ efficiency specification.
Navitas’ reference designs dramatically accelerate customer developments, minimize time-to-market, and set new industry benchmarks in energy efficiency, power density and system cost, enabled by GaNFast power ICs. These system platforms include complete design collateral with fully-tested hardware, embedded software, schematics, bill-of-materials, layout, simulation and hardware test results.
In this case, the ‘Common Redundant Power Supply’ (CRPS) form-factor specification was defined by the hyperscale Open Compute Project, including Facebook, Intel, Google, Microsoft, and Dell. Now, Navitas’ CRPS185 platform delivers a full 3,200 W of power in only 1U (40 mm) x 73.5mm x 185 mm (544 cc), achieving 5.9 W/cc, or almost 100 W/in3 power density. This is a 40% size reduction vs, the equivalent legacy silicon approach and easily exceeds the Titanium efficiency standard, reaching over 96.5% at 30% load, and over 96% stretching from 20% to 60% load, creating a ‘Titanium Plus’ benchmark, critical for data center operating models.
The CRPS185 uses the latest circuit designs including an interleaved CCM totem-pole PFC with full-bridge LLC. The critical components are Navitas’ new 650V GaNFast power ICs, with robust, high-speed integrated GaN drive to address the sensitivity and fragility issues associated with discrete GaN chips. Additionally, GaNFast power ICs offer extremely low switching losses, with a transient-voltage capability up to 800 V, and other high-speed advantages such as low gate charge (Qg), output capacitance (COSS) and no reverse-recovery loss (Qrr). As high-speed switching reduces the size, weight and cost of passive components in a power supply, Navitas estimates that GaNFast power ICs save 5% of the LLC-stage system material cost, plus $64 per power supply in electricity over 3 years.
Compared to traditional ‘Titanium’ solutions, the Navitas CRPS185 3,200 W ‘Titanium Plus’ design running at a typical 30% load can reduce electricity consumption by 757 kWh, and decrease carbon dioxide emissions by 755 kg over 3 years. This reduction is equivalent to saving 303 kg of coal. Not only does it help data center clients achieve cost savings and efficiency improvements, but it also contributes to the environmental goals of energy conservation and emission reduction.
In addition to data center servers, this solution can also be widely used in applications such as switch/router power supplies, communications, and other computing applications.
“The popularity of AI applications like ChatGPT is just the beginning. As data center rack power increases by 2x-3x, up to 100 kW, delivering more power in a smaller space is key,” said Charles Zha, VP and GM of Navitas China. “We invite power designers and system architects to partner with Navitas and discover how a complete roadmap of high efficiency, high power density designs can cost-effectively, and sustainably accelerate their AI server upgrades.”
Original – Navitas Semiconductor