Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide
Rev 3.4
vicorpower.com
Page 92 of 97
Apps. Eng. 800 927.9474
800 735.6200
F
Factorized Power Architecture (FPA).
A power
distribution architecture that is inherently more granular
and leverages an allocation of the DC-DC converter
functions consistent with efficient power distribution
principles. An optimal power distribution architecture
should efficiently support demanding low voltage, high
current loads. FPA is a higher level power architecture that
offers dramatic improvements in onboard power distribution
systems, in performance, reliability and economy.
Fault Tolerant Configuration.
A method of parallel
operation, using output Oring diodes, in which the failure
of a single supply (module) will not result in a loss of
power. The total current of the parallel system must not
exceed the load requirements to a point where the failure
of a single unit will not result in a system overload.
FET.
Field Effect Transistor. A majority carrier-voltage
controlled transistor.
FinMod.
A flangeless /finned packaging option available
on Vicor’s VI-/MI-Family converters and accessory modules.
FlatPAC.
A Vicor AC-DC switcher available with one, two
or three outputs, with total power rating from 50 – 600 W.
Floating Output.
An output of a power supply that is
not connected or referenced to any other output, usually
denoting full galvanic isolation. Floating outputs can
generally be used as either positive or negative outputs.
Non floating outputs share a common return line and are
hence DC referenced to one another.
Foldback Current Limiting.
A type of protection circuit
where the output current decreases as the overload
increases. The output current reaches a minimum as the
load approaches a short circuit condition.
Forward Converter.
A switching power supply in which
the energy is transferred from the input to the output
during the “on” time of the primary switching device.
G
GATE IN.
The GATE IN pin of the module may be used to
turn the module on or off. When GATE IN is pulled low,
the module is turned off. When GATE IN is floating (open
collector) the module is turned on. The open circuit voltage
of the GATE IN pin is less than 10 V, referenced to –Vin.
A GATE OUT / GATE IN connection is necessary to run
Driver / Booster configurations.
GATE OUT.
The GATE OUT pin is the clock pulse of the
converter. It is used to synchronize Booster modules to a
Driver module for high power arrays.
Ground.
An electrical connection to earth or some
other conductor that is connected to earth. Sometimes
the term “ground” is used in place of “common,” but
such usage is not correct unless the connection is also
connected to earth.
Ground Loop.
An unintentionally induced feedback
loop caused by two or more circuits sharing a common
electrical ground.
H
Haversine.
A waveform that is sinusoidal in nature, but
consists of a portion of a sine wave superimposed on
another waveform. The input current waveform to a
typical offline power supply has the form of a haversine.
Headroom.
Used in conjunction with series pass
regulators, headroom is the difference between the input
and output voltages.
Heat Sink.
A medium of high thermal mass that can
absorb (sink) heat indefinitely with negligible change in
temperature. Heat sinks are not necessarily needed with
Vicor modules, and their use is highly dependent on the
individual application, power and ambient temperature.
High Line Input.
The maximum steady-state input
voltage on the input pin.
Hipot.
Abbreviation for high potential, and generally
refers to the high voltages used to test dielectric
withstand capability for regulatory agency electrical safety
requirements.
Hold-Up Capacitor.
A capacitor whose energy is used to
provide output voltage for a period after the removal of
input voltage.
Hold-Up Time.
The length of time a power supply can
operate in regulation after failure of the AC input. Linears
have very short hold-up times due to the energy stored
on the low-voltage secondary side output capacitors.
Switchers have longer times due to higher-voltage
primary-side energy storage capacitors.
Hot Swap.
Insertion and extraction of a power supply
into a system while power is applied.
I
I-Grade.
Industry standard where the operation
temperature of a device does not drop below –40°C.
26. Glossary of Technical Terms
Summary of Contents for VI-200 Series
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