May 1958 Radio-Electronics
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. 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 most 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
By H. Barr
Compiled 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 process.
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 layer.
Barrier-layer capacitance See depletion-layer capacitance.
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
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 arrangement.
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 configuration.
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
Current amplification, current gain Ratio of output to input
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
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 process.
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 temperature.
Diffusion transistor Transistor relying on diffusion for carrying
current; for example, ordinary junction transistor.
Diode Two-terminal semiconductor device that rectifies.
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 voltage.
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
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
Gate Electrode on a field-effect transistor.
Germanium Common semiconductor material, usually used for making
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 in semiconductors.
Header Part of a transistor which the leads pass through to
Heat sink Something that will absorb and dissipate a large amount
of heat without getting hotter.
Holes Positively charged current carriers in semiconductors.
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
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
Leakage current That portion of cut-off current due to surface
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
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 in-put, 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
Peak inverse voltage Maximum reverse voltage rating for a diode
or a transistor.
Photodiode Semiconductor diode whose reverse current increases
Photoresistor semiconductor resistor whose resistance drop when
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 occurs.
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 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 characteristics.
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
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
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
Silicon Common semiconductor, used in transistors and diodes.
Small-signal analysis Consideration of only small excursions
from the no-signal bias, so that the transistor can be represented by a linear equivalent
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
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 purpose.
Tandem transistor Two transistors in one package, internally
Tetrode transistor Any of several types of transistors with
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
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 layer,
Transition-layer capacitance See depletion-layer capacitance.
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 moving.
Traps Any of several imperfections in a crystal which can trap
Unijunction transistor Transistor made for switching circuits,
having only one junction.
Varistor A semiconductor device with a symmetrical but nonlinear
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 with it.
Posted July 18, 2014