ICE
www.recom-international.com PP-43REV: 0/2014
I.C.E Technology
ICE (Innovation in Converter Excellence)
Technology uses a combination of techniques
to minimise internal heat dissipation and
maximise the heat transfer to ambient to create
a new converter series which offers high end
performance at a price which is si-
gnificantly lower than conventional specialist
converters.
The exact details of this technology must
remain secret, but the following brief resume
describes the main features of this
technological breakthrough:
Minimising internal heat dissipation
The difference between the input power and
the output power is the internal power
dissipation which generates heat within the
converter.
If the converter is inefficient at converting
power, then adding external heat sinks, base-
plates or fans are remedies that cure the
symptoms rather than address the illness.
First and foremost, the converter must have the
highest possible efficiency over the entire input
voltage range and load conditions. Most power
converters are designed to be most efficient at
25°C, full load and nominal input voltage and
thus offer a compromise performance when
lightly loaded or operated at the maximum
ambient temperature.
ICE Technology uses state-of-the-art
techniques to improve power convertion
efficiency by approximately 2% compared to
standard converters. A two per cent improve-
ment may not sound much, but the difference
between a converter with 88% efficiency and
one with 90% efficiency is a 17% reduction in
the dissipated power. In addition, when lightly
loaded, the converters enter a power saving
mode and draw only a few milliamps from the
supply.
Maximising heat transfer
The rate of heat transfer between a hot body
and its cooler surroundings is given by
Fourier’s Law:
q=-k.ΔT
where
q = rate of heat transfer
k = thermal conductivity
and ΔT = temperature difference
If k can be made larger, then the rate of heat
transfer can still match or exceed the rate of
heat generation at lower temperature
differences ΔT and the converter will have an
extended operating temperature range.
Techniques to improve thermal
conductivity
ICE Technology splits the thermal conductivity
problem into two areas and attacks each area
seperately using different techniques.
Firstly, the internal heat transfer to the case is
maximised by a combination of novel
converter construction and clever thermal
design.
ICE converters use a construction where the
hottest components (the switching FET, the
transformer and the synchronous rectification
FETs) are placed closest to the case wall. This
method of construction makes the
manufacture of the converter more difficult, but
this lack of compromise reduces greatly the
internal thermal impedance.
Secondly, the rate of transfer of heat to the
surroundings is improved by a novel case
construction which incorporates a built-in heat
sink. The case is also made from thick aircraft
grade aluminium rather than thin nickel-plated
copper to provide a better thermal junction
between the case and the high thermal
conductivity silicone potting material used
inside the converter.
Maximising high temperature
performance
The final technique used in the construction of
ICE Technology converters is to use high
temperature internal components. The
maximum operating temperature of a
converter is dependent on the lowest
maximum permissible operating temperature
of any the components used. If the capacitors
are rated up to +85°C and the FETs are rated
at +160°C, then the limiting factor is the ca-
pacitor temperature of +85°C.
The temperature of the ferrite core used in the
transformer is also an important limiting
factor. If the transformer core temperature
exceeds the Curie temperature of the ferrite,
then the transformer rapidly loses
performance.
ICE Technology converter uses high
temperature grade components to permit a
case temperature of +115°C maximum. This
allows operation at up to +85°C ambient
without the need for fans to blow air over the
converter.
Electromagnetic Compatibility
Although high temperature performance is a
significant feature of ICE Technology design, it
does not end there.
ICE Technology also addresses the need for
electromagnetic compatibility by incorporating
a built-in EN55022 Class B grade filter inside
the converter. The converter has been
designed from the ground up to meet EMC
requirements rather than a conventional
design process where first the converter is
optimised for performance and then an
external filter is added to combat the
conducted interference.
By including the filter on the main PCB of the
converter, the track path lengths and
impedances between the filter and the noise-
generating components are reduced to the
minimum and consequently smaller value
filter components can be used that fit into the
compact case dimensions of the Powerline+
converters without compromising on filter
performance.
Safety and Protection
ICE Technology converters are fully protected
from output short circuits, overload, output
over-voltage and over-temperature. In addition,
they feature under-voltage lockout that will
automatically disable the converter if the input
voltage falls below the minimum level.
The output is current limited which means that
temporary overloads can occur without the
converter shutting down. When overloaded, the
output voltage will decrease to keep the
maximum power constant. For the 40W and
50W converters, if the overload is too high, the
converter will go into hiccup short circuit
protection mode. In this mode, the converter
will attempt to reconnect power every 10-20
milliseconds.
Output overvoltage protection is monitored by
a separate and independent feedback circuit
and an internal thermistor sensor is used to
protect the converter against overheating.
POWERLINE+ Application Notes
DC/DC-Converter
ICE
Technology
ICE Technology
