May 1958 Radio-Electronics
Wax nostalgic about and learn from the history of early electronics. See articles
published 1929 - 1948. All copyrights hereby acknowledged.
A few new terms have been added to the transistor lexicon since
1958, but this list from Radio-Electronics magazine contains
more than 150 definitions that are still useful today. It is amazing
that this list was created just a decade after the transistor was
invented, and now half a century later the mot commonly used terms
have not changed much. In looking over the words, there are very
few that need to be added to the original (which I did).
By H. Barr
from several sources and presented here are over 150 terms unique
to the transistor field. General radio-electronic-television terms
that are not directly related to transistors are excluded, as well
as specialized scientific terms we are not likely to run across.
Many of the terms defined have several meanings. Only the particular
meaning appropriate to the transistor field is given. Also, many
of the words have various spellings and no attempt has been made
to list all possible variations.
Acceptor Impurity used to produce p-type semiconductor.
Alloy-diffused transistor Transistor in which
the base is diffused in, and the emitter alloyed.
Alloy process Process for making junctions by
melting an acceptor or donor on the surface of the semiconductor
and letting it refreeze.
Alloy transistor Transistor made by the alloy
Alpha Emitter-to-collector current gain.
For a junction transistor alpha is less than one.
Alpha-cutoff frequency The high frequency at
which the value of alpha is down to 0.7 of its low-frequency value.
Back bias See reverse bias.
Barrier See junction.
Barrier capacitance See depletion-layer capacitance.
Barrier layer, barrier region See depletion
Barrier-layer capacitance See depletion-layer
Base Electrode on a transistor.
Base resistance Resistance in series with the
base lead in the common T equivalent circuit of a transistor.
Base ring Ohmic contact to the base region of
power transistors, made in the shape of a ring.
Beta Base-to-collector current gain of a transistor.
Bipolar junction transistor Transistor made
with alternating layers of N and P type semiconductors.
Bonded-barrier transistor Transistor made by
alloying when the alloying material is on the end of a wire.
Boundary, p-n See p-n junction.
Button Piece of metal for alloying onto the
base wafer in making alloy transistors.
Carriers Particles which carry current, specifically
either electrons or holes.
Collector Electrode on a transistor.
Collector capacitance Depletion-layer capacitance
associated with the collector junction.
Collector efficiency Ratio of useful power output
to final stage power supply power input, usually expressed in percentage.
Collector family Set of characteristic curves
for a transistor, in which collector current and collector voltage
are used as variables.
Collector junction On junction transistors,
the junction between the collector and the base.
Collector resistance Resistance in series with
the collector lead in the common-T equivalent circuit of a transistor.
Common base Configuration for amplifiers, in
which the base is common to both input and output circuits.
Common collector Configuration for amplifiers,
in which the collector is common to both input and output circuits.
Common emitter Configuration for amplifiers,
in which the emitter is common to both input and output circuits.
Complementary symmetry Any of several types
of circuits using both p-n-p and n-p-n transistors in a symmetrical
Conductivity A property of a semiconductor expressing
how easily current may flow through it; the reciprocal of resistivity.
Configuration Type of amplifier circuit, depending
on which electrode is common to input and output; for example, common-emitter
Coupling Method of passing the signal from one
stage to another; for example, capacitor coupling, transformer coupling.
Crossover distortion Harsh type of distortion
produced by incorrectly biased class-B amplifiers.
Crystal Regular array of atoms in a solid; for
example, single-crystal germanium.
Current amplification, current gain Ratio of
output to input current.
Cutoff current Collector current with no emitter
current and normal collector-to-base bias.
Czochralski technique Method of growing large
single crystals by pulling them from a molten state; usually used
to grow germanium and silicon single crystals.
Depletion layer Region near a junction without
current carriers, on reverse bias.
Depletion-layer capacitance Capacitance of the
depletion layer, which is a function of reverse voltage.
Depletion-layer transistor Any of several types
of transistors which rely directly on motion of carriers through
depletion layers for their operation; for example, spacistor.
Derating Reducing ratings on a transistor, especially
the maximum power dissipation rating at higher temperatures.
Diamond lattice The crystal structure of both
germanium and silicon as well as diamond.
Diffused-base transistor Any of several types
of drift transistors in which the base is diffused in.
Diffused emitter-collector transistor, diffused E-C transistor
Transistor in which both the emitter and collector are made by the
Diffusion Movement of carriers from heavily
populated regions to regions without as many carriers, similar to
slow diffusion of ink through a still glass of water; also similar
movement of donors and acceptors at high temperatures.
Diffusion process Method for making junctions
by diffusing acceptors or donors into a semiconductor at a high
Diffusion transistor Transistor relying on diffusion
for carrying current; for example, ordinary junction transistor.
Diode Two-terminal semiconductor device that
Dissipation Loss of electrical energy into heat.
Donor Impurity used to produce n-type semiconductor.
Doping Adding impurities to change the resistivity
of semiconductors and to make n-type or p-type.
Dot See button.
Double-base diode See Unijunction transistor.
Double-diffused transistor Junction transistor
in which both the emitter and the base are diffused in.
Drain Electrode on a field-effect transistor.
Drift Movement of carriers because of applied
Drift transistor Transistor relying on drift
for carrying current; compare diffusion transistor.
Electroforming Process of creating p-n junctions
by passing current through point contacts.
Electrons Negatively charged current carriers.
Emitter Electrode on a transistor.
Emitter junction On junction transistors, the
junction between the emitter and the base.
Emitter resistance Resistance in series with
the emitter lead in the common-T equivalent circuit of a transistor.
Equivalent circuit A circuit which approximates
the actual transistor under some conditions.
Field-effect transistor Type of transistor relying
on movement of a depletion layer to vary the conduction between
two electrodes, the source and the drain.
Floating junction Junction through which no
net current flows.
Forward bias Large-current bias as applied to
a diode; opposite to reverse bias.
Fused-junction transistor See alloy transistor.
Fused transistor See alloy transistor.
Gain Ratio of out/input voltage levels.
Gallium arsenide Compound semiconductor (GaAs)
for high frequency applications.
Gate Electrode on a field-effect transistor.
Germanium Common semiconductor material, usually
used for making transistors.
Grounded base See common base.
Grounded collector See common collector.
Grounded emitter See common emitter.
Grown-diffused transistor Junction transistor
with junctions formed by diffusion of impurities near a grown junction.
Grown-junction transistor Junction transistor
with junctions formed by adding impurities to the melt while the
crystal was being grown.
Hall effect Transverse voltage produced by current
travelling at right angles to a magnetic field; especially prominent
Header Part of a transistor which the leads
pass through to get outside.
Heat sink Something that will absorb and dissipate
a large amount of heat without getting hotter.
Holes Positively charged current carriers in
Hook transistor Four-layer transistor with a
built-in hook amplifier for a collector.
h-parameters Four commonly used parameters for
specifying the small-signal behavior of a transistor.
Hybrid parameters See h-parameters.
Impurity Small addition to a semi-conductor,
especially a donor or an acceptor.
Injector Electrode on a spacistor.
Intrinsic-region transistor Four-layer transistor
with an intrinsic region between the base and the collector.
Intrinsic semiconductor Neither n-type nor p-type,
containing roughly equal numbers of electrons and holes.
i-type Intrinsic semiconductor
Junction Region separating two different types
of semiconductor, especially p-n junction.
Junction diode A diode which uses a junction
to get a rectifying characteristic.
Junction transistor Most common type of transistor,
using two junctions with the base region between them.
k-factor Numerical value indicating stability
of amplifier circuit.
Large-signal analysis Consideration of large
excursions from the no-signal bias, so that the nonlinear, switching
properties of the transistor are important.
Leakage current That portion of cut-off current
due to surface effects.
MADT transistors Micro-Alloy Diffused-base Transistors.
Majority carriers Whichever type is more plentiful,
i.e. electrons in n-type and holes in p-type.
Meltback process Method of making junctions
by melting a correctly doped semiconductor and allowing it to refreeze.
Meltback transistor Junction transistor made
by the meltback process.
Melt-quench transistor Junction transistor made
by quickly cooling a melted-back region.
Microalloy transistor Transistor using very
thin alloyed collector and emitter, usually made in the same shape
as a surface-barrier transistor.
Minority carriers Whichever type is less plentiful,
i.e. electrons in p-type and holes in n-type.
Modulator Electrode on a spacistor.
Noise figure The ratio of actual equivalent
noise input to thermal noise input, usually expressed in decibels.
n-p-i-n transistor Intrinsic-region transistor
with p-type base and n-type emitter and collector.
n-p-n-p transistor Hook transistor with p-type
base, n-type emitter, and hook collector.
n-p-n transistor Junction transistor with p-type
base and n-type collector and emitter.
n-type Semiconductor doped with a donor so that
electrons are more plentiful than holes.
Parameters Set of numbers which characterize
a device, especially a transistor.
Peak inverse voltage Maximum reverse voltage
rating for a diode or a transistor.
Photodiode Semiconductor diode whose reverse
current increases upon illumination.
Photoresistor semiconductor resistor whose resistance
drop when illuminated.
Phototransistor Photodiode with a built-in hook
amplifier; physical construction is the same as a junction transistor.
Pinch-off In a field-effect transistor, the
effect of having reduced source-to-drain current as far as possible.
Pinch-off voltage The voltage at which pinch-off
p-n-i-p transistor Intrinsic-region transistor
with n-type base and p-type emitter and collector.
p-n junction Junction between p-type and n-type
areas of a semiconductor.
p-n-p-n transistor Hook transistor with n-type
base, p-type emitter, and hook collector.
p-n-p transistor Junction transistor with n-type
base, and p-type collector and emitter.
Point contact A sharp point placed on a semiconductor
for making point-contact devices.
Point-contact diode A diode which uses a point
contact to get a rectifying characteristic.
Point-contact transistor Old-style transistor
made by forming junctions by the unpredictable process of electroforming.
Power gain Ratio of output power to signal input
power, not to be confused with collector efficiency.
Power transistor A transistor, usually an alloy-junction
type, made to handle high currents and high power.
p-type Semiconductor doped with an acceptor
so holes are more plentiful than electrons.
Q-factor Numerical 'quality' based on gain-bandwidth
Rate-grown transistor Junction transistor with
junctions formed by varying the rate of the crystal's growth.
Recombination Simultaneous elimination of both
an electron and a hole.
Rectifier Any device which has a non-symmetrical
volt-ampere curve, and which therefore can be used to rectify a.c.;
for example, junction diode.
Resistivity A property of a semiconductor directly
related to the resistance to electricity; the reciprocal of conductivity.
Reverse bias Small-current, high-voltage bias
as applied to a diode; opposite to forward bias.
Reverse current The small current that flows
in a diode under reverse bias.
Saturation The low-resistance condition in a
transistor when the collector voltage is very small.
Saturation current That portion of cutoff current
not due to surface effects; do not confuse with saturation.
Saturation resistance The ratio of voltage to
current in saturation.
Seed Special single crystal used to start the
growth of large single crystals by the Czochralski technique.
Selenium Semiconductor used mainly in rectifiers.
Semiconductor Material which conducts by both
electrons and holes.
Silicon Common semiconductor, used in transistors
Small-signal analysis Consideration of only
small excursions from the no-signal bias, so that the transistor
can be represented by a linear equivalent circuit.
Source Electrode on a field-effect transistor.
Space-charge layer See depletion. layer.
Spacistor Type of transistor relying on modulation
of carriers injected into a depletion layer.
Stability Lack of tendency toward thermal runaway.
Stability factor A number which measures the
stability of a transistor stage.
Stabilization Process of introducing stability
into a circuit.
Surface barrier A barrier formed automatically
at a surface due to trapped electrons held at the surface.
Surface-barrier transistor Transistor using
surface barriers instead of p-n junctions.
Symmetrical transistor Transistor in which collector
and emitter are made identical, so either can be used for either
Tandem transistor Two transistors in one package,
internally connected together.
Tetrode transistor Any of several types of transistors
with four electrodes.
Thermal runaway Condition in which the dissipation
in the transistor increases with higher temperature so fast that
the temperature keeps rising.
Thermistor Temperature-sensitive resistor, usually
made from a semiconductor.
Transistor Semiconductor device with three or
more electrodes used for amplification.
Transistor action The physical mechanism of
amplification in a junction transistor.
Transition layer, transition region See depletion
Transition-layer capacitance See depletion-layer
Transit time Average time it takes a minority
carrier to diffuse from emitter to collector in a junction transistor.
Trapping Holding of electrons or holes by any
of several mechanisms in a crystal, preventing the carriers from
Traps Any of several imperfections in a crystal
which can trap carriers.
Unijunction transistor Transistor made for switching
circuits, having only one junction.
Varistor A semiconductor device with a symmetrical
but nonlinear volt-ampere characteristic.
Voltage amplification, voltage gain Ratio of
output voltage to input voltage.
Whisker A point contact.
Zener diode A diode which breaks down at the
Zener voltage, used for voltage regulators.
Zener voltage That reverse voltage at which
a large current starts to flow, caused by breaking down the crystal.
Zone refining A technique for purifying crystals
by passing a melted zone through the crystals, which drags the impurities
Posted July 18, 2014