active region - Area on a device characteristic where the ratio between applied voltage and resulting current is constant. That is, the device is not operating in regions such as saturation, cutoff, or ohmic.

amplification - Process of changing the amplitude of a signal with minimum alteration in its shape.

amplifier - Assembly that produces an output quantity such as voltage or current in linear proportion to an applied input quantity. The output quantity is not necessarily larger than the input quantity.

analog-to-digital converter (ADC) - Circuit that converts an analog signal to a digital signal whose binary value represents the amplitude of the original analog signal.

anode - Positive terminal of a bipolar device.

astable multivibrator - Oscillator circuit that produces a rectangular wave output.

bandwidth - Range of frequencies for which the gain is at least 0.707 of midband gain.

bias line - Graphical technique in circuit analysis which describes the bias circuit, external to a device, on the device transfer characteristic curve.

bias(ing) - Fixed dc voltage applied to a circuit that is intended to set a device’s operation at a particular point on its characteristic curve.

bipolar - Type of device whose functioning involves both majority and minority charge carriers.

bipolar junction transisto - r. See BJT

BJT - Bipolar junction transistor is a 3-layer device containing both types of semiconductor material (either in p-n-p or n-p-n form). It typically has three terminals.

Bode plot - Graph of gain or phase shift versus frequency for a circuit.

body resistance - Inherent resistance of the block(s) of material composing an electronic device—one aspect of how a practical device deviates from ideal.

bridge - Network of four components arranged in a square with identical opposite pairs of elements. The input is attached across one diagonal, and the output across the other.

candela - Unit of light intensity in SI.

cascade amplifier - Amplifier with two or more stages in which the output of one stage serves as the input to the next.

cascode amplifier - High frequency amplifier made up of a common-emitter amplifier with a common-base amplifier in its collector network.

cathode - Negative terminal of a bipolar device.

characteristics - Set of graphs that display any operating feature of an electronic device, such as collector current vs. collector-emitter voltage for a set of different base currents.

chip - Common name for an integrated circuit. Many chips are cut from a single wafer of silicon that has been doped and etched to form many elements and components.

clamping - Process of shifting an input ac signal to a different zero point.

clipper - Circuit that cuts off some portion of an input signal.

clipping - Failure of a circuit to respond to signals above a certain amplitude, causing distortion of the output signal.

CMOS - Complimentary MOS: digital integrated circuitry in which both n- and p-channel MOSFETs are used.

common - Path for current returning to the power supply from a circuit.

common base (emitter, etc.) - Configuration in which the base (emitter, etc.) the terminal of a three-terminal device is common to both the input and output loops of the circuit.

common-mode rejection - Ratio of the differential gain of an op-amp to its common-mode gain.

comparator - Op-amp circuit that compares two input voltages and provides a DC output that indicates which input is greater.

conduction angle - Portion of a half wave, expressed in degrees, during which a silicon-controlled rectifier is conducting.

constant-current source - Circuit that provides constant current to a changing load.

contact resistance - Resistance at the contacts with the material of an electronic device—one aspect of how a practical device deviates from ideal.

conversion efficiency - For an amplifier, the ratio of output ac power to input dc power.

corner frequency - Frequency at which the gain of an amplifier has dropped to 0.707 of midband value.

crystal oscillator - An oscillator with a piezoelectric crystal in its feedback network to maintain a stable frequency of oscillations.

current mirror - Circuit consisting of two matching transistors with the collector of one connected to the bases of both, thus producing the same collector current in each transistor.

current-limiting circuit - Protection circuitry that prevents the output current from exceeding a maximum value under an overload or short-circuit condition.

cut-off - State of a semiconductor device in which the current is a minimum.

cut-off frequency - See corner frequency

Darlington pair connection - Two bipolar junction transistors with their collectors connected together and the emitter of one connected to the base of the other.

demodulation - Process of extracting a signal that has been impressed on a carrier wave.

depletion - Application of an electric field that repels majority carriers in a volume of semiconductor material.

depletion region - Region near the junction of a semiconducting device that has few free carriers because electrons and holes have combined.

detection - See Demodulation

die - Another term for chip.

differential amplifier - Amplifier in which the output voltage is proportional to the difference between the voltages applied to its two input terminals.

digital-to-analog converter (DAC) - Circuit that converts a digital signal to an analog signal whose amplitude is proportional to the binary value of the digital signal.

diode - Two-terminal device that conducts unidirectionally.

discrete component - Package containing only a single electrical or electronic component.

donor atom - Atom with five valence electrons added to a semiconductor to increase the number of electrons in it.

donor level - Energy level of the valence band in a semiconductor with doping, which reduces the energy gap between the valence band and the conduction band.

doping - Process of adding small quantities of particular impurities to an intrinsically pure semiconductor in order to alter its conducting properties.

dropout voltage - Minimum value by which the input voltage of a voltage regulator must exceed the output voltage for regulation to occur.

efficacy - Measure of the ability of a device to produce a desired effect.

electroluminescence - Emission of light by a device when electrical energy is supplied.

electron volt - Energy required to move a charge of one electron through a potential difference of 1 V; equals 1.602 × 10^-19 J.

enhancement - Application of an electric field that attracts majority carriers to a volume of semiconductor material.

equivalent circuit - Combination of elements intended to mimic the characteristics of an electronic device with mathematical aspects that are simpler than those of the actual device. See also model

extrinsic material - Semiconducting material that has had its conducting properties altered by doping; n-type material contains extra electrons; p-type material contains extra holes.

feedback - Application of a portion of an amplifier’s output to its input. It is used to improve amplifier performance or to cause oscillation.

feedback pair - Two bipolar junction transistors with the collector of the npn connected the emitter of the pnp and the collector of the pnp connected the base of the npn.

FET - Field-effect transistor

filter - Part of a power supply that converts the rectified sine wave from the rectifier into a dc voltage with ripple.

foldback limiting - Protection circuitry that causes the output current to decrease to a low value under an overload or short-circuit condition.

follower - Voltage amplifier whose output "follows" the input, and so has a gain of approximately one.

forward-bias - Voltage applied to a p-n junction (positive to p, negative to n) that diminishes the depletion region and increases the flow of majority carriers.

Fourier analysis - Mathematical technique for describing a complex waveform as the sum of the harmonics of a fundamental.

free - Of electrons, those that are only loosely bound to an atom or ion—they are able to migrate readily through a material under the application of small electric fields.

frequency modulation - Process of varying the frequency of a signal such that the instantaneous value of the frequency is proportional to the amplitude of a control voltage or signal.

frequency-shift keying - Form of frequency modulation in which the value of a digital signal sets the frequency at one of two values.

full-wave rectification - Converting ac to dc using both halves of each ac input cycle.

fundamental - Lowest frequency component of a waveform.

gain - Amplification factor of an amplifier, the ratio of output to input.

gain margin - Value in decibels of the amplitude of the ßA factor of a feedback amplifier at the frequency for which the phase shift of ßA is 180°.

gain-bandwidth product - Transistor parameter that indicates the maximum possible product of gain and bandwidth.

gradient - Regular change in a quantity along a given line or dimension; a the rate of change of such quantity.

half-power frequency - See corner frequency

half-wave rectification - Converting ac to dc using only half the input of each full ac cycle.

harmonic - A sine wave that is an integral multiple of a fundamental frequency. See also fundamental

hole - Vacancy in a normally filled site in a valence shell or band, created by doping with an acceptor atom. A hole is mobile and conducts as if it were a positive charge.

hybrid - Involving the combination of unlike quantities or materials, as for example, voltage and current.

hybrid IC - Integrated circuit that is composed of monolithic components and either thin-film or thick-film components.

IC component - Package containing more than one electrical or electronic component in a single package.

ideal device - Device that performs its function perfectly; e.g., an ideal transducer converts without loss all the energy applied to it.

ideal diode - Diode that conducts perfectly in one direction and not at all in the opposite direction (zero resistance in one direction and infinite resistance in the opposite direction).

integrated circuit (IC) - Collection of solid-state devices combined with other circuit elements printed on a single chip.

interface circuit - Circuit that links input and output signals of different types of logic families with each other or with analog signals.

intrinsic carriers - Charges constituting a current that are able to move simply because of the nature of the material and its temperature. See also extrinsic

ionization - Process by which an electron is removed from an atom by the application of some form of energy.

ionization potential - Electrical potential that is just sufficient to remove an electron from a shell of its atom.

JFET - Junction field-effect transistor

junction - The area of contact between volumes of n- and p-type extrinsic material.

lattice - Regular spacing in three-dimensions of atoms in a crystal.

leakage current - Minority carrier current in a reverse-biased junction in the absence of injected minority carriers.

light-emitting diode - Diode that will emit light when forward biased.

linear circuit - Circuit in which one quantity changes in direct proportion to another quantity.

load line - Graphical technique in circuit analysis which describes the output circuit, external to a device, on the device output characteristic.

load-line analysis - Method of describing the operation of an electronic device using the intersection of a line representing the load on the device and a graph line of the device’s characteristics. The intersection is called the Q-point.

load regulation - Measure of the change in load voltage as load current changes from no-load to full-load value.

majority carriers - Charge carriers made abundant in the doping process of extrinsic material—electrons in n-type material or holes in p-type material.

mesa transistor - Transistor produced by etching away a part of the area above the collector region to form a plateau on which the base and emitter regions are then formed.

minority carriers - Charge carriers that are deficient in extrinsic material—holes in n-type material or electrons in p-type material.

model - Representation of a system (either concrete or abstract) intended to assist in understanding the system, either by simplifying or emphasizing particular features of the system. Consider the differences among "model airplane," "atomic model," and "fashion model." See also equivalent circuit

modulation - Process of combining a signal with a carrier wave (which is usually at a much higher frequency).

monolithic IC - Circuit in which all components are formed as pn junctions on or within a semiconductor substrate.

monostable multivibrator - Circuit with one stable output state that, when triggered, switches to an unstable state for a fixed period of time and then returns to the stable state.

MOSFET - Metal-oxide-semiconductor field-effect transistor.

negative feedback - Circuitry in which a feedback signal is 180° out of phase with the input signal.

no-bias - Circuit that contains no fixed applied voltage.

Nyquist diagram - Plot of the ßA factor of a feedback amplifier as a vector on the complex plane for frequencies from zero to infinity.

offset potential - Potential difference at which a diode or transistor begins to conduct at significant currents. It is also called the firing potential or threshold potential, and is symbolized as V_T.

op-amp - Operational amplifier, a high-gain amplifier with an output that corresponds to the difference between two input signals.

oscillator - Electronic circuit that produces a periodic output waveform with no voltage other than dc applied.

parallel resonance - Condition occurring in a parallel RLC network at the frequency where the reactance of the inductor equals the reactance of the capacitor.

peak inverse voltage - See PIV

phase margin - 180° minus the phase shift at the frequency at which the gain is 0 dB.

phase-locked loop - Circuit in which the phase of the output signal is compared to the phase of the input signal and adjustments made such that the output signal will lock onto and track the input signal.

phase-shift oscillator - Oscillator with a feedback network consisting of three RC high-pass networks connected in series that produce 180° phase shift.

piecewise linear equivalent circuit - Equivalent circuit with elements chosen to approximate the device’s characteristic with straight-line segments.

piezoelectric effect - Property of a crystal that produces a voltage across opposite faces due to mechanical stress and vice versa.

PIV - Peak inverse voltage, the maximum reverse-bias potential that can be applied to a diode before entering the Zener region; also called PRV.

planar transistor - Transistor produced by forming the base and emitter regions within the collector region rather than above it.

port - A pair of terminals.

power supply - Circuit that converts a sinusoidal voltage into a dc voltage.

Q-point - Point on a device’s characteristic from which it operates. Set by the dc components in the circuit, the quiescent point sets the zero for ac variations. It is the intersection of the load line with a characteristic curve.

quiescent point - See Q-point

rectification - Process of converting ac to dc.

reverse-bias - Voltage applied to a p-n junction (negative to p, positive to n) that enlarges the depletion region and increases the flow of minority carriers.

ripple - Ratio of the ripple voltage to the dc voltage expressed as a percentage.

ripple voltage - Small variations in the amplitude of the voltage at the output of the filter in a power supply.

saturation - (1) Condition in a semiconductor in which no further increase in current results, no matter how much additional voltage is applied. (2) In a BJT, the state in which the voltage from collector to emitter is a minimum, typically 100 mV. (3) In an FET, the state in which an increase in the voltage from drain to source does not result in a significant increase in non-zero drain current.

semiconductor - Any material that possesses a resistivity much higher than good conductors and much lower than good insulators.

series regulator - Voltage regulator in which the control element is in series with the output voltage.

series resonance - Condition occurring in a series RLC network at the frequency where the reactance of the inductor equals the reactance of the capacitor.

shunt voltage regulator - Voltage regulator in which the control element is in parallel with the output voltage.

signal - Electrical waveform that contains information, varying according to (for example) an audio or video input.

single-crystal - Any material composed only of the repetitive structure of one kind of unit crystal.

small signal - AC operation of an electronic device in a small enough vicinity around the q-point that the slope of the device transfer characteristic in that vicinity can be considered constant.

source regulation - Measure of the change in load voltage as source voltage changes.

strobe - Control signal whose value determines whether a circuit is enabled or disabled.

switching regulator - Regulator in which regulation is maintained by switching the power control devices between on and off states.

temperature coefficient - Number that expresses the rate of change of a quantity with temperature as, for example, the temperature coefficient of resistance.

tetravalent atom - Atom containing four electrons in its (outer) valence shell.

thick-film IC - Integrated circuit with passive elements deposited on a substrate using screening and firing processes and active elements added on the surface as discrete components.

thin-film IC - Integrated circuit with passive elements deposited on a substrate using a sputtering or vacuum process and active elements added on the surface as discrete components.

threshold voltage - Voltage level for a diode or transistor that results in a significant increase in drain current. See also offset potential

tilt - Measure of the loss in amplitude of a pulse from the leading edge to the trailing edge of the pulse.

transconductance factor - For an FET, the ratio of the change in drain current to the change in gate voltage that induced it; symbol, g_m; unit, siemen.

transfer characteristic - Graph that displays the relationship between the input and output quantities of a device.

transistor - Semiconductor device useful for amplifying or switching electrical signals.

tuned oscillator - Oscillator in which component values in an LC network determine the frequency of oscillations.

two-port network - Generalized model of a linear circuit that has two input and two output terminals.

unipolar - Device whose functioning involves only majority charge carriers.

valence - Outer shell of an atom containing the electrons that determine the element’s chemical characteristics.

voltage-controlled oscillator (VCO) - Oscillator whose output frequency varies with a modulating input voltage.

wafer - Thin slice of semiconductor crystal on which many IC circuits (chips) are formed.

Wien bridge oscillator - Oscillator with a feedback network consisting of a series RC network and a parallel RC network in a bridge circuit.

yield rate - Percentage of the chips obtained from a single wafer that meet specifications.

Zener potential - The reverse-bias voltage at which a diode will experience a sharp increase in reverse current.

Zener region - Portion of the current-voltage characteristic of a diode which shows a sharp increase in reverse current at the Zener potential.