It’s finally happening: the first redundant power supplies using GaN FETs. They shrink the footprint by 30% and improve total system efficiency to 94%


Telcodium introduces the AC series of redundant
power supplies that replace the typical three-module power supply architecture
(that have two power supply bricks and an intermediate bus converter [IBC])
with a single power module with redundant ac feeds. It is the industry’s first
redundant power supplies using gallium nitride (GaN) field-effect transistors


The power module operates at 94% true system
efficiency (TSE) — reducing average energy loss by 13% or more. To achieve the
same TSE with the typical three-module power supply, the bricks and IBC would
each need to yield a 97% efficiency — which exceeds the 80Plus Titanium
specification (95% x 95% = 90.25%). This has yet to be demonstrated by any
other power supply manufacturer. Additionally, the new module is 30% smaller
than the typical versions with two bricks and eliminates the standalone IBC.


high efficiency and size reduction were made possible by the use of
JEDEC-qualified 650-V GaN FETs from Transphorm and also some innovative designing.
The smaller size is a big deal for the targeted market for this power supply,
which includes the data center, server, and telecom markets.





In the typical server, a redundant power supply has
two bricks that provide power to the IBC. The IBC’s function is to manage the
two bricks and perform the power distribution to the internal components such
as the motherboard, CPU, memory, disks, and SSDs. To determine the efficiency
of the system, you need to multiply the efficiency of each of the power modules
and the IBC. So if the efficiency of the brick is 90% and the efficiency of the
intermediate bus converter is also 90%, then the True System Efficiency (TSE)
is only 81%. Therefore, in a 300-W server, 57 W would be wasted as heat by the
power supply system and only 243 W would be available to the other components.
Compare that to the Telcodium power supply (the ac series): Its GaN design and
patented technologies include the IBC section in the supply and provide from
92% to 94% TSE. They are 30% smaller and only use 16 W of heat while delivering
243 W to the system. This is a 14% savings of energy. Multiplied by the number of
servers used in a data center or telecom center, that means thousands of
dollars saved. Another point to make when comparing power supplies is to
understand how the power supply manufacturer presents the efficiency specs.
Some do not include efficiency of the IBC as part of overall efficiency. For
example, they might say that their power supplies meet the 80Plus Titanium spec
requirements and are 95% efficient, but then you have to connect it to an IBC,
which is probably also 95%, so the TSE is really 95% x 95% = 90.25%. The
important thing for data centers is to recognize the capital expenses, the
operating expenses, and the reliability. Telcodium says that customers can save
20% to 30% in square footage (capital) and 5% to 20% in energy savings (operating),
and the MTBF is 500 kH compared to typical failure rates of 100 kH. For more details about the AC series, see