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 94 of 97
Apps. Eng. 800 927.9474
800 735.6200
N
Nominal Input.
The center value for the input voltage
range.
Nominal Value.
A usual, average, normal, or expected
operating condition. This stated value will probably not be
equal to the value actually measured.
O
Offline.
A power supply that receives its input power
from the AC line, without using a 50 / 60 Hz power
transformer prior to rectification and filtering, hence
the term “offline” power supply.
Open Frame.
A power supply where there is no external
metal chassis; the power supply is provided to the end
user essentially as a printed circuit board that provides
mechanical support as well as supporting the components
and making electrical connections.
Operating Temperature.
The range of temperatures in
which a unit can operate within specifications.
Optoisolator.
An electro-optical device that transmits a
signal across a DC isolation boundary.
ORing Diodes.
Diodes used to isolate supplies from one
another under a fault condition.
Output Filtering.
Filter used to reduce switching power
supply noise and ripple.
Output Good.
A power supply status signal that indicates
the output voltage is within a certain tolerance. An output
that is either too high or too low will deactivate the
Output Good signal.
Output Impedance.
The ratio of change in output
voltage to change in load current.
Output Noise.
The AC component that may be present
on the DC output of a power supply. Switch-mode power
supply output noise usually has two components: a lower
frequency component at the switching frequency of the
converter and a high frequency component due to fast
edges of the converter switching transitions. Noise should
always be measured directly at the output terminals with
a scope probe having an extremely short grounding lead.
Output Power Rating.
The maximum power in watts
that the power supply can provide and still maintain safety
agency approvals.
Output Voltage Accuracy.
See Setpoint Accuracy.
Overload Protection.
A power supply protection circuit
that limits the output current under overload conditions.
Overshoot.
A transient output voltage change exceeding
the high limit of the voltage accuracy specification caused
by turning the power supply on or off, or abruptly
changing line or load conditions.
Overtemp Warning.
A TTL compatible signal that indicates
an overtemperature condition exists in the power supply.
Overvoltage Protection (OVP).
A circuit that either
shuts down the power supply or crowbars the output
in the event of an output overvoltage condition.
P
Parallel Boost.
VI- /MI-200 Family Booster modules may
be added to a Driver to create multi-kilowatt arrays.
Boosters do not contain any feedback or control circuitry.
Parallel Operation.
Connecting the outputs of two or
more power supplies together for the purpose of
obtaining a higher output current. This requires power
supplies specially designed for load sharing.
PARD.
Periodic And Random Deviation. Referring to the
sum of all ripple and noise components on the DC output
of a power supply, regardless of nature or source.
Peak Power.
The absolute maximum output power that a
power supply can produce without immediate damage.
Peak power capability is typically well beyond the
continuous output power capability and the resulting
average power should not exceed rated specifications.
Pi Filter.
A commonly used filter at the input of a
switching supply or DC-DC converter to reduce reflected
ripple current. The filter usually consists of two shunt
capacitors with inductance between them.
Post Regulator.
A secondary regulating circuit on an
auxiliary output of a power supply that provides regulation
on that output.
Power Fail.
A power supply interface signal that gives a
warning that the input voltage will no longer sustain full
power regulated output.
Power Factor.
The ratio of true power to apparent power
in an AC circuit. In power conversion technology, power
factor is used in conjunction with describing AC input
current to the power supply.
Preload.
A small amount of current drawn from a power
supply to stabilize its operation.
Primary.
The input section of an isolated power supply, it
is connected to the AC mains and hence has dangerous
voltage levels present.
26. Glossary of Technical Terms
Summary of Contents for VI-200 Series
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