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a soft-switching topology that is
inherently low-noise, making it
easier to develop high-performance
systems.
Size and Packaging
Today electronic systems are often
space constrained. Even if the
goal is not to make the system as
small as possible, such as products
housed in standardized 19” rack
units, reducing the size of the power
system allows the space saved to be
used to add additional functionality.
Any calculation of size should also
consider the peripheral components
required by the regulator. With
higher levels of integration and
high switching frequency, the
size and number of peripheral
components can be reduced, which
can potentially offer a greater
space saving than simply picking a
regulator in a smaller package.
The package types available don’t
only determine the space required:
often smaller packages can be
located closer to the load, enabling
more accurate regulation at the
load and faster transient response.
In addition to size, weight can also
be an important factor, particularly
in applications where the equipment
can move. Examples of such
systems range from hand-carried
portable equipment to automotive
electronics and drones.
Operating Temperature
& Thermal Performance
Regulators cannot be100%efficient,
so they will always dissipate heat
that must be removed. If a heatsink
is required, this can significantly
increase both the size and weight
of the power system. Failure to
dissipate heat can also impact the
system performance in other ways:
for example, in lighting or display
applications if the regulator causes
an increase in temperature of the
LEDs, this will reduce the intensity
and change the wavelength, and
therefore the hue, of the light
generated.
The regulator must function reliably
across the range of temperatures to
which it can be exposed. In general,
more efficient regulators will be able
to operate at higher temperatures,
as they do not need to dissipate
so much heat, but products from
different suppliers can vary widely
so it is important to check the data
sheet.
Additional Features
In addition to the criteria described
above, your application may require
some specific functionality, which
can limit choice. Examples of these
additional features include:
Paralleling Capability: if regulators
can be paralleled, then higher
output currents can be delivered.
Not all regulators can have
their outputs paralleled, as with
many topologies this will cause
instability.
Constant Current Output: in
battery applications, a constant
voltage is needed to supply
the load, but constant current
is required for charging. Some
regulators offer outputs that can
be configured both as constant
current and constant voltage,
making them ideal for these
systems.
Soft start: the ability to ramp
up the voltage slowly helps to
ensure the power system is
stable, even when large amounts
of capacitance are connected to
the output of the regulator.
Overvoltage protection: regulators
that have protection to ensure
they cannot deliver more than
the defined output voltage ensure
that the load will not be damaged
even during a fault. Other
protection circuitry might disable
the regulator if the input voltage
is out of range.
Transient response: some loads
rapidly change the current
they demand. A fast transient
response ensures that the
regulator can deliver the power
needed, without large output
capacitors to store energy.
Conclusion
Although regulators are conceptually
simple components – they take a
voltage at the input and deliver a
different voltage at the output – there
are many factors that determine the
best regulator for your application.
Carefully considering the criteria
outlined above will help to ensure
you pick the ideal regulator for your
system.
New-Tech Magazine Europe l 55