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%





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 (FETs).


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.


The 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 include 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 mother board, CPU, memory, disks, and SSDs. To determine the efficiency of system
you need to multiply the efficiency of each 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 – 94%
TSE. They are 30% smaller and only use 16-W as 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, 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 – 30% in square
footage (capital) and 5 – 20% in energy savings (operating), and the MTBF is
500 kh compared to typical failure rates of 100 kh. For the AC series details, see