Definition of Terms

Product Information
Definition of Terms
ABSOLUTE MAXIMUM RATINGS are limiting values
of operation and should not be exceeded under the worst
conditions. These values are chosen to provide acceptable
serviceability of the device. The equipment manufacturer
should design so that initially, and throughout life, no
absolute maximum value is exceeded. If exceeded, even if
the device continues to operate, its life may be considerably
The absolute maximum output current ratings are the
maximum allowable under any condition. In application,
the allowable output current will be limited by number of
outputs conducting, duty cycle and timing, ambient temperature, heat sinking and/or forced cooling, and other heat
In those devices that include internal current limiting,
fault conditions that produce excessive output current will
activate device current-limiting circuitry. In this mode,
some device outputs will come out of saturation and
dissipate an increased amount of power and the junction
temperature will increase. Overcurrent limiting is intended
to protect the device against transient overloads and should
not imply short-circuit protection.
Under any set of conditions, the specified maximum
junction temperature (usually +150°C) should not be
exceeded. In those devices that include an internal thermal
shutdown, fault conditions that produce excessive junction
temperature will activate device thermal shutdown circuitry. These conditions can be tolerated, but should be
TYPICAL VALUES and TYPICAL CHARACTERISTIC CURVES are given for circuit or system baseline
design only and are usually at the nominal operating
voltage and an ambient temperature of +25°C rather than
over operating ranges. Although these values are indicative
of the peak distribution (mode) for a large number of
production lots, they should not be expected for any
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particular device or single production lot. They are representative values, rather than actual values, that are characteristic of the values that are expected to occur the most
frequently under normal operating conditions.
Where the typical value is intended to describe a range of
observed values, the typical value corresponds to the
statistical mode, that is, the value that occurs most frequently for a large number of production lots, or predominantly intended to be achieved. Where there is more than
one mode, the typical value is undefined.
Note that a statistical typical value does not imply the
shape of the underlying distribution of actual values.
Distributions may contain maverick values, outliers, or a
well-formed normal distribution while having the same
typical value. System performance must allow for any
device performing within the specified limits.
CHARACTERISTICS LIMITS are those values that are
warranted only under the test conditions shown. System
requirements are often given with device parameters, for
example, logic input voltage (but not input current) and
maximum clock frequency.
The absolute magnitude convention is used for electrical characteristics limits where the limits are defined
Maximum [minimum] limit: the greater [smaller]
magnitude limit of a range of like-signed values;
if the range includes both positive and negative
values, both limiting values are maximums (the
minimum is implicitly zero).
The algebraic convention is used for magnetic characteristics limits where negative flux densities are
defined as less than zero (-50 G is less than +10 G). The
minimum value is therefore the most negative value, the
maximum value is the most positive value, and zero has no
special significance.
SPECIAL SYMBOLS are sometimes used by Allegro MicroSystems to simplify circuit drawings.
NOTE — See Allegro Publication 26005 for complete terms and definitions for IC Outputs.
given for optimum device performance. Operation outside
these conditions is permitted (within the Absolute Maximum Ratings) without any implied level of performance.
It is recommended that equipment manufacturers consult
their local sales office whenever device applications
involve unusual electrical, mechanical, or environmental
operating conditions.
PRODUCT PREVIEW is used to advise customers of
proposed additions to the product line. The specifications
given are target or goal specifications and may, therefore,
change without notice. Allegro MicroSystems, Inc. reserves
the right to not manufacture proposed devices that have
been announced as “product preview”; samples may not be
available yet. It is imperative that you contact your local
sales office for details of current status and latest specifications prior to making any circuit design commitments.
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ADVANCE INFORMATION (engineering prototypes,
meaning limited sample availability) or PRELIMINARY
INFORMATION (preproduction or first production) are
used to advise customers of additions to the product line
that, nevertheless, still have “preproduction” status. Details
may, therefore, change without notice although it is expected that preliminary performance data is representative
of “full production” status. Contact your local sales office
for details of current status and latest specifications.
INTERIM DATA is used to describe a publication that is
incomplete. The status of the products described may be
advance, preliminary, or production. It is intended that a
more complete description will follow.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
Copyright ©1993-2013, Allegro MicroSystems, LLC
The information contained in this document does not constitute any representation, warranty, assurance, guaranty, or inducement by Allegro to the
customer with respect to the subject matter of this document. The information being provided does not guarantee that a process based on this information will be reliable, or that Allegro has explored all of the possible failure modes. It is the customer’s responsibility to do sufficient qualification
testing of the final product to insure that it is reliable and meets all design requirements.
For the latest version of this document, visit our website:
26004-AN, Rev. B
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.