New Industry Products

Bel Power and Transphorm Collaborate on a Family of AC-DC Power Supplies

February 03, 2021 by Gary Elinoff

The new devices are aimed at data center applications and supply 12 VDC at output powers ranging from 1.5 to 3.2 kW

The new TET Series of power supplies from Bel employ Transphorm’s high voltage gallium nitride (GaN) FETs, underlining the growing dominance of wide bandgap semiconductors in the field of high power electronic applications.


Bel Power and Transphorm Collaborate On a Family of AC-DC Power Supplies Figure
Image courtesy of Transform


The six member TET series of power supply units (PSU) are AC to DC front end supplies, highlighted by TET3000 series. Members of this family are the industry’s first AC-DC supplies employing GaN technology in their AC-to-DC bridgeless totem-pole power factor correction (PFC) power stage that have achieved Titanium efficiency. 

The TET3000 series, with improvements in firmware, has given rise to the somewhat more powerful TET3200 series. The TET1500, TET200, TET2200 and TET2500 series range in power levels from 1.5 to 2.5 kW 


Summary of Specifications for the new power Supplies

The basic parameter of the six new series of devices are outlined below


  Wattage in Watts

AC Input 
Voltage (VAC)

Power Density
Watt per Cubic In.

Size in Inches
TET1500 1500 90 to 305 35 2.14 x 1.57 x 12.66
TET2000 2000 90 to 264 51 7.68 x 3.39 x 1.57
TET2200 2200 90 to 264 53.1 3.4 x 1.5 x 7.7
TET2500 2500 90 to 264 62 7.68 x 3.39 x 1.57
TET3000 3000 90 to 300 31.7 21.85 x 2.72 x 1.60
TET3200 3200 90 to 300 33.8 21.85 x 2.72 x 1.60


All units communicate via I2C bus. Differences between individual members of each of the six series include airflow and the connectors employed. More specifics are available from BEL, with links to the data sheets of each of the six series of PSUs

All members of each of the six series achieve 96 percent efficiency or better at high line with a main output of 12 VDC. Thus, each PSUs has earned an 80 Plus Titanium rating. 


80 Plus Titanium Efficiency

What it means is that for a 230 volt input, PSUs achieve the following efficiency levels.

  • 90% efficiency at 10% load
  • 94% efficiency at 20% load
  • 96% efficiency at 50% load
  • 94% efficiency at 100% load 


Gallium Nitride is changing the way Data Centers are Powered

GaN enjoys fundamental advantages over old-school silicon devices. Transphorm’s GaN FETs, as an example, can enable the efficiencies of  AC to DC power factor correction (PFC) stages to more than 99 percent. This means greater power in the same-sized PSU, for great improvements in power density.

Greater efficiency also means less generation of troublesome heat, which can compromise reliability. The units described in this article feature a FIT of less than 1.0, or less than one failure for each one billion hours of real-world use. 


The Partnership between Bel and Transform

A synergistic alliance between a GaN semiconductor producer and a manufacturer of power solutions makes it possible to produce a superior product.

According to Ian Warner, Business Development Manager, Bel Power Solutions, “We’ve been designing with Transphorm’s GaN for more than six years now. The efficiency and reliability we’ve been able to achieve to date has helped us create the TET family of supplies that are exceeding customer expectations with an unparalleled solution. We’re changing what’s possible in data centers and Transphorm is a contributor to that movement.” 

As per Philip Zuk, VP of Worldwide Technical Marketing and NA Sales at Transphorm, “We’ve seen high voltage GaN positively disrupt industries over the past few years” He goes on to say that, “The data center market is next. Transphorm’s technology performance is proven in excess of 10 kW in various applications. Our device cost is driving down closer to silicon with each generation. And, we set the industry benchmarks for quality and reliability. We’re unsurpassed in that area, making our GaN devices an optimal choice for data center solutions.” 



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