GaN enables Seasonic’s 1.6kW Bridgeless Totem-Pole PFC Platform
Transphorm Inc. announced that Seasonic Electronics Co. uses Transphorm’s high voltage (HV) GaN FETs in its new 1600W bridgeless totem-pole power factor correction (PFC) platform: the 1600T. The 1600T is the power supply manufacturer’s highest performing PFC platform to date at greater than 99 percent efficiency.
Notably, the introduction of GaN delivers a two percent efficiency increase and 20 percent power density increase over Seasonic’s previous Silicon-based platform. The 1600T platform will be scaled and deployed in various catalog products targeting the Charger (e-scooters, industrial, etc.), Gaming, Server, and PC power markets.
“When researching semiconductor technologies that would enable us to reach world-leading efficiency levels, gallium nitride stood out as an attractive alternative to Silicon,” said Paul Lin, Director of Research and Development, Seasonic.
“We knew the bridgeless totem-pole PFC was the topology we would use in our first high voltage GaN power platform. So, we needed power semiconductors capable of successfully capitalizing on that topology. What’s more, we wanted a GaN solution that could be backed by our standard warranty.
“We ultimately opted for Transphorm’s FETs within the 1600T given their proven performance and reliability that allowed us to meet those requirements,” Lin concluded.
The 1600T platform employs Transphorm’s TP65H035WS device, a 650V GaN FET with an RDS(on) of 35mΩ in a standard TO-247 package. The transistor achieves increased efficiency in hard-and soft-switched circuits, providing power systems engineers options when designing products.
In addition, the TP65H035WS pairs with commonly-used gate drivers to simplify designs while controlling costs.
Transphorm GaN typically delivers greater headroom and noise immunity when compared to other available GaN FETs. The TP65H035WS’ typical gate threshold is 4V with a maximum gate voltage of ±20V.
Beyond the technology itself, Transphorm offers in-depth field application support and hands on training given GaN’s relative newness in high voltage applications. Seasonic leveraged the semiconductor company’s experts to strengthen the design itself while quickening time to market.
For example, guidance provided helped Seasonic’s team ramp on use of a simple, low-cost digital signal processor (DSP) to control the totem-pole PFC.
Transphorm also aided in the platform’s component selection and system layout, ensuring optimal GaN performance. Ultimately, the co-development directly impacted Seasonic’s ability to drive up thermal efficiency while increasing power output—generating a HV GaN platform capable of delivering on Seasonic’s vision.