1998 Product of the Year Award Winner

Flat-transformer module slashes cost,
weight of high-performance power supplies

Traditionally, a major impediment to reducing the size of power supplies
has been the bulky size and weight of the power transformer. The year 1998
saw Flat Transformer Technology take a major step to overcome this limitation
with its breakthrough FTI Flat Transformer Module.

The FTI flat-transformer modules from
Flat Transformer Technology halve power
transformer costs to allow economical
compact, high-frequency power supplies.

Long under development, the patented flat-transformer module can produce
power transformers that cost 50% less than conventional transformers and
combine higher performance and smaller size. The flat transformer promises
to make possible future generations of high-current, low-voltage, high-frequency
dc/dc and ac/dc supplies at competitive costs, without being limited by
the shape and size of the transformer.

In the FTI transformer, a single winding with tiny, multiple pressed
ferrite cores replaces a bulky single core with multiple windings. Because
the magnetic cores incorporate simple pressed parts, they can be mass produced
at a very low cost.

The flat transformer's network of winding elements incorporates a small
number of primary winding turns and acts as a single transformer with very
low leakage inductance. Without the lengthy leakage-inducing bulk magnet
wire common in conventional transformers, the transformer can operate with
faster switching times and lower losses and stress on ancillary parts.

Moreover, the transformer's compact magnetic core geometry eliminates
thermal hot spots and reduces heat dissipation, thus allowing higher packaging
density. By virtue of its lower inductance and heat dissipation, the transformer
can use lower-power components and smaller heat sinks–both factors that
also contribute to reduced manufacturing cost.

Typical performance characteristics include a leakage inductance of
4 nH/module, efficiencies exceeding 99%, an 8- or 12-mm height profile,
and an operating temperature range of –40° to +130°C. The transformer's
nominal operating frequency ranges from 250 to 500 kHz.

Supplied preassembled with the secondary circuit and interconnections
provided, a basic 150-W flat-transformer module measures just 2.12 (L)
x 0.63 (W) x 0.46 (H) in. The modules can be ganged together for higher
power. The transformer is suited for half-bridge, full-bridge, push-pull,
and forward converter technologies. ($5.50 ea/5,000–stock.)

Flat Transformer Technology
Costa Mesa, CA
James Lau 714-850-7320
Fax 714-850-1163