About this glossary
This is PCBasic’s comprehensive glossary of electronic terms used across design, manufacturing, and testing.
While many of these terms have formal IEC/IEEE or IPC meanings, in production they often carry practical interpretations specific to the factory floor.
Each entry below explains the term in plain, actionable language, to help engineers, buyers, and QA professionals understand documentation, test data, and design feedback quickly and accurately.
How to use
Designers/Engineers: Clarify circuit terminology and communicate effectively with our manufacturing engineers.
Purchasing/PMs: Understand datasheets, component specifications, and assembly notes.
Quality/Inspection: Identify root causes, interpret reports, and align with industry terminology.
If you can’t find a term, tell your PCBasic representative — we’ll add it in the next revision.
A
AC (Alternating Current)
An electric current that reverses direction periodically, typically 50 Hz or 60 Hz. Used in power grids and some signal circuits.
Accuracy
The closeness of a measurement to its true value. Often expressed as ±% of reading.
Active Component
A component that requires power to operate or can control current flow—e.g., transistors, ICs, diodes.
Adapter
A device used to connect incompatible interfaces or convert plug formats.
ADC (Analog-to-Digital Converter)
A circuit that converts an analog voltage into a digital value.
Additive Noise
Unwanted electrical signal added to the desired signal.
Amplifier (AMP)
A circuit or device that increases the amplitude of a voltage or current signal.
Ampere (A)
SI unit of electric current; one coulomb of charge per second.
Analog Signal
A continuously variable signal that represents changing quantities such as voltage or temperature.
AND Gate
A digital logic gate whose output is HIGH only when all inputs are HIGH.
Annealing
Heating metal to relieve stress and improve conductivity or ductility.
Anode
The positive electrode where current flows into a device (for diodes, current enters the anode).
Antenna
A conductive structure that transmits or receives electromagnetic waves.
Anti-static
Material or process that prevents buildup of static electricity.
Aperture
Opening or window through which energy or signals pass; in PCB design, the shape defined for photoplotting.
Apparent Power (VA)
Product of RMS voltage and current in AC circuits; includes both active and reactive power.
Arcing
Uncontrolled electrical discharge through air or insulation breakdown.
Assembly Drawing
Engineering drawing showing component placement and orientation for PCBA.
Attenuation
Reduction in signal amplitude as it travels through a medium or circuit.
Auto-Router
Software that automatically routes PCB traces according to design rules.
B
Bandwidth
The range of frequencies a system can transmit or process effectively.
Bar Graph Display
Visual display representing analog values as a bar of LEDs or LCD segments.
Base (Transistor)
The control terminal of a bipolar transistor.
Battery
Device that stores and provides electrical energy by chemical reaction.
Bias
A DC voltage or current applied to set the operating point of an electronic component.
Binary
A numbering system using only 0 and 1, fundamental to digital electronics.
Bit (Binary Digit)
Smallest unit of digital data; either 0 or 1.
Bleeder Resistor
Resistor placed across capacitors to discharge stored voltage safely.
Blocking Capacitor
Capacitor used to prevent DC while allowing AC to pass.
BNC Connector
Bayonet-type RF connector used for test and signal cables.
Board Stack-up
Arrangement of layers in a multilayer PCB, defining copper, dielectric, and plane order.
Bonding Wire
Fine wire connecting semiconductor die to package leads.
Boolean Logic
Mathematical system of true/false operations used in digital circuits.
Bootstrap Circuit
Feedback configuration increasing voltage swing or impedance.
Breakdown Voltage
The voltage at which insulation or semiconductor junction fails.
Bridge Rectifier
Four-diode arrangement converting AC to DC.
Brownout
A partial drop in voltage that may cause logic errors or resets.
Buffer
A device that isolates or amplifies signals without distortion; also a temporary data storage region.
Bus
A set of conductors or traces used for data or power distribution between devices.
Bypass Capacitor
Capacitor used to shunt noise or AC components to ground, stabilizing DC supply lines.
C
Capacitance
Ability of a component to store electrical charge, measured in farads (F).
Capacitor (Cap)
Device storing energy in an electric field between two plates separated by dielectric.
Carrier Frequency
Base frequency of a modulated signal.
Cathode
Negative electrode of a device (e.g., current exits through cathode in a diode).
Celsius (°C)
Temperature scale used in most electronics specifications.
Ceramic Capacitor
Capacitor with a ceramic dielectric; used for filtering, decoupling, timing.
Chip
Integrated circuit die or packaged semiconductor device.
Chopper
Circuit that converts DC to AC or pulses for control.
Circuit
A complete path allowing current flow from source through load and back.
Closed Loop
System using feedback to control output, e.g., servo systems, regulators.
Coil (Inductor)
Wound conductor storing energy in magnetic field.
Common Mode Noise
Noise appearing equally on two lines relative to ground.
Comparator
Circuit comparing two voltages and outputting logic HIGH or LOW.
Compliance Voltage
Max voltage that a current source can maintain at set current.
Conduction
Movement of charge through a medium.
Conductor
Material with low resistance allowing electric current flow.
Connector
Mechanical/electrical interface joining circuits or cables.
Continuity Test
Check for unbroken electrical connection.
Control Signal
Signal used to govern operation of another circuit or device.
Coulomb (C)
SI unit of charge; 1 C = 1 A × 1 s.
Crosstalk
Unwanted coupling of signals between adjacent conductors.
Crystal Oscillator
Stable frequency source using quartz crystal resonance.
D
DAC (Digital-to-Analog Converter)
Converts digital signals into corresponding analog voltages.
Darlington Pair
Two transistors connected for high current gain.
DC (Direct Current)
Electric current flowing in one direction only.
Decibel (dB)
Logarithmic unit expressing ratios of power or voltage.
Decoder
Logic circuit converting coded inputs into unique outputs.
De-coupling Capacitor
Capacitor used to filter power supply noise near ICs.
Dielectric
Insulating material between capacitor plates or PCB layers.
Differential Pair
Two complementary traces carrying equal and opposite signals to reduce noise.
Diode
Semiconductor allowing current in one direction.
Dip Switch
Set of small toggle switches in a single package.
DIP (Dual Inline Package)
IC package with two parallel rows of pins for through-hole mounting.
Duty Cycle
Percentage of time a signal is active during one period.
Dynamic Range
Ratio between the largest and smallest measurable signals of a system.
E
E-core Transformer
Transformer using E-shaped laminated or ferrite core.
Earth (Ground)
Common electrical reference point for voltage measurements.
ECL (Emitter Coupled Logic)
High-speed logic family using differential amplifiers.
Eddy Current
Circulating current induced in conductors by changing magnetic fields.
EEPROM
Electrically erasable programmable read-only memory.
Efficiency
Output power divided by input power, expressed as a percentage.
Electromagnet
Magnet formed when current passes through a coil.
Electromagnetic Interference (EMI)
Unwanted signal coupling from external electromagnetic fields.
Electromotive Force (EMF)
Voltage generated by a source such as a battery or generator.
Electron
Negatively charged particle orbiting atomic nuclei.
Emitter
One terminal of a bipolar transistor through which current exits.
Encapsulation
Sealing electronic components in protective material.
Energy (Joule)
Capacity to perform work; 1 J = 1 W × 1 s.
ESD (Electrostatic Discharge)
Sudden flow of electricity between charged objects—can damage semiconductors.
ESR (Equivalent Series Resistance)
Effective internal resistance of a capacitor at AC.
Etching
Chemical removal of unwanted copper to form circuit patterns.
Excitation Voltage
Input voltage applied to sensors or bridges.
Exponential Response
Signal change following an exponential curve, common in RC circuits.
F
Farad (F)
Unit of capacitance; one coulomb per volt.
Feedback
Portion of output returned to input to control behavior.
Ferrite Bead
Magnetic component used to suppress high-frequency noise.
Filter
Circuit that passes desired frequencies and attenuates others.
Firmware
Permanent software programmed into ROM or flash memory.
Flash Memory
Non-volatile rewritable memory used in microcontrollers and storage.
Float (Floating Node)
Unconnected circuit node with undefined voltage.
Flux
Substance used during soldering to remove oxides and improve wetting.
Flyback Diode
Diode placed across inductive load to absorb voltage spikes.
Forward Voltage (Vf)
Voltage drop across a forward-biased diode.
Frequency (Hz)
Number of cycles per second in a periodic signal.
Fuse
Safety device that opens circuit when current exceeds rated value.
G
Gain
The ratio of output to input signal amplitude (voltage, current, or power).
Galvanic Isolation
Electrical separation between circuits to prevent current flow while allowing signal or power transfer (e.g., transformers, optocouplers).
Gate (Logic Gate)
A digital circuit that performs a basic logical operation such as AND, OR, or NOT.
Gate (FET)
The control terminal of a field-effect transistor regulating current between source and drain.
GHz (Gigahertz)
One billion cycles per second (10⁹ Hz). Used for high-frequency systems like RF and microwaves.
Ground (GND)
Reference point for all voltages in a circuit; also a safety path for current leakage.
Ground Bounce
Voltage fluctuation of ground potential due to switching currents in digital ICs.
Ground Plane
Large copper area on PCB providing low-impedance return path and EMI shielding.
Guard Ring
Conductive ring surrounding a sensitive node to prevent leakage or interference.
H
Half-Wave Rectifier
Circuit that converts only one half-cycle of AC into DC using a single diode.
Hall Effect Sensor
Sensor producing voltage proportional to magnetic field strength.
Harmonic Distortion
Unwanted multiples of fundamental frequency added to output signal.
Heat Sink
Component or structure that dissipates heat from a device into ambient air.
Hertz (Hz)
Unit of frequency; one cycle per second.
High-Pass Filter
Filter that passes high frequencies and attenuates low ones.
High-Side Switch
Switching device connected to positive supply line.
Hold Time
Minimum time input data must remain stable after a clock transition.
Humidity Sensor
Device that measures moisture level in air or environment.
Hybrid IC
Integrated circuit combining semiconductor devices with passive elements on a substrate.
I
IC (Integrated Circuit)
Miniaturized circuit containing transistors, resistors, and capacitors fabricated on a semiconductor die.
IEC (International Electrotechnical Commission)
Organization defining global electrical and electronic standards.
Impedance (Z)
Combined opposition to AC current flow, including resistance and reactance, measured in ohms.
Inductance (L)
Property of a conductor to oppose changes in current, measured in henries (H).
Inductor (Coil, Choke)
Wound conductor storing energy in a magnetic field.
Input Impedance
Effective impedance seen by the source driving a circuit input.
Input Offset Voltage
Small differential voltage required between amplifier inputs to produce zero output.
Inrush Current
Surge of current when power is first applied to a device or capacitor.
Insulator
Material that resists the flow of electric current.
Integrator
Circuit producing an output proportional to the time integral of its input.
Interference
Unwanted disturbance superimposed on a signal (can be EMI or crosstalk).
IoT (Internet of Things)
Network of connected embedded devices exchanging data wirelessly.
J
Jack
Female connector that mates with a plug.
Joule (J)
Unit of energy; one watt-second (1 J = 1 W × 1 s).
Jumper
Wire or shunt used to connect two points manually on a circuit or board.
Junction
Region where two semiconductor materials meet, such as PN junction.
Junction Temperature (Tj)
Temperature at the active region of a semiconductor device.
K
Kelvin (K)
Absolute temperature scale; 0 K = −273.15 °C.
Keying Slot / Polarization
Physical feature preventing incorrect connector orientation.
Kilo (k)
Prefix denoting ×1000.
Kirchhoff’s Laws
Fundamental laws for current and voltage in circuits:
1. KCL – The sum of currents entering a node equals the sum leaving.
2. KVL – The sum of voltages around a closed loop is zero.
L
Laminated Core
Magnetic core built from thin sheets to reduce eddy currents.
Latch
Bistable circuit that holds a binary state until changed by control signal.
LC Filter
Filter network combining inductors and capacitors for frequency selection.
LED (Light Emitting Diode)
Semiconductor device that emits light when current flows through it.
Leakage Current
Small unintended current that flows through insulation or junctions.
Line Regulation
Change in power supply output due to variations in input voltage.
Load
Any device or circuit drawing current from a source.
Load Regulation
Change in output voltage with varying load current.
Logic Level
Voltage representing digital HIGH or LOW.
Loop Gain
Overall gain around a feedback loop.
M
Magnetism
Physical phenomenon produced by moving electric charges or magnetic materials.
MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor)
High-efficiency transistor widely used for switching and amplification.
Microcontroller (MCU)
Integrated computer containing CPU, memory, and peripherals for embedded control.
Microprocessor (MPU)
Central processing unit executing instructions for computation.
Milli (m)
Prefix meaning one-thousandth (1/1000).
MIM Capacitor
Metal-Insulator-Metal capacitor used in RF and IC design.
Modulation
Varying a carrier signal to transmit data (e.g., AM, FM, PWM).
Monostable Multivibrator (One-shot)
Circuit generating a single output pulse of defined duration.
Multimeter
Instrument measuring voltage, current, and resistance.
Multiplexer (MUX)
Circuit selecting one of several inputs to connect to a single output line.
N
NAND Gate
Logic gate producing LOW output only when all inputs are HIGH.
Noise Margin
Minimum difference between logic thresholds and signal levels ensuring reliable operation.
Nominal Value
Ideal or labeled value of a component.
NOT Gate (Inverter)
Logic gate producing output opposite to input.
NPN / PNP Transistor
Bipolar transistor types differing by semiconductor polarity and current direction.
Nyquist Frequency
Half the sampling rate; the maximum frequency that can be accurately represented in sampled data.
O
Ohm (Ω)
Unit of electrical resistance; 1 Ω = 1 V/A.
Ohm’s Law
Fundamental relation: V = I × R.
Op-Amp (Operational Amplifier)
High-gain differential amplifier used for analog signal processing.
Open Circuit
Incomplete path where current cannot flow.
Optocoupler
Device transferring signal between isolated circuits via light.
Oscillator
Circuit generating a repetitive waveform (sine, square, etc.).
Overcurrent Protection
Circuit mechanism limiting current to prevent damage.
Overvoltage
Voltage exceeding rated level for a device.
P
Parallel Circuit
Configuration where components share the same voltage but different current paths.
PCB (Printed Circuit Board)
Insulating board supporting and interconnecting electronic components via copper traces.
PCBA (Printed Circuit Board Assembly)
PCB with components mounted, soldered, and tested.
Peak-to-Peak Voltage (Vpp)
Difference between maximum and minimum waveform amplitude.
Phase
Relative timing difference between two periodic signals.
Photodiode
Semiconductor generating current when exposed to light.
Photonics
Technology of generating and controlling light for communication or sensing.
Piezoelectric Effect
Electric charge generated by mechanical stress on certain materials.
Pin Header
Connector with male pins for plugging or soldering.
Pitch
Center-to-center spacing between adjacent pins or leads.
PLL (Phase-Locked Loop)
Feedback system locking oscillator frequency to a reference.
Potentiometer (Variable Resistor)
Adjustable resistor for tuning voltage or current.
Power Factor (PF)
Ratio of real power to apparent power in AC circuits.
Power Supply
Device that provides regulated electrical energy to a circuit.
Pull-Up / Pull-Down Resistor
Resistor forcing input line to a defined logic level when otherwise floating.
PWM (Pulse Width Modulation)
Technique controlling average power by varying pulse duty cycle.
Q
Q-Factor (Quality Factor)
Measure of resonator sharpness or selectivity; ratio of stored to dissipated energy per cycle.
Quartz Crystal
Piezoelectric element used for precise frequency control in oscillators.
R
Radiation
Emission or transfer of energy as electromagnetic waves.
RC Circuit
Circuit combining resistor and capacitor for timing or filtering.
Rectifier
Device converting AC to DC.
Reference Voltage
Stable voltage used as comparison for measurements.
Relay
Electromechanical switch controlled by an electrical signal.
Resistor (R)
Component opposing current flow, converting electrical energy into heat.
Resolution
Smallest change in signal that can be detected or represented.
Resonance
Condition where inductive and capacitive reactances cancel, yielding maximum response.
Ripple Voltage
Residual AC voltage in a DC output after rectification/filtering.
Rise Time
Time taken for a signal to change from 10% to 90% of its final value.
S
Sampling Rate
Number of samples per second taken in digital signal processing.
Saturation
Condition where an amplifier or transistor output cannot increase despite input.
Schmitt Trigger
Circuit providing hysteresis to clean noisy input signals.
SCR (Silicon Controlled Rectifier)
Four-layer device acting as a switch when triggered.
Secondary (Transformer)
Winding that delivers transformed voltage/current from primary coil.
Semiconductor
Material with conductivity between conductor and insulator (e.g., silicon).
Sensitivity
Change in output per unit change in input; used for sensors.
Shielding
Metal or conductive enclosure blocking EMI.
Short Circuit
Low-resistance path causing excessive current.
Signal-to-Noise Ratio (SNR)
Ratio of desired signal power to noise power.
Sine Wave
Smooth periodic oscillation fundamental to AC analysis.
SMD (Surface Mount Device)
Component designed for mounting directly onto PCB surface pads.
SMT (Surface Mount Technology)
Method of assembling components on PCB surface without leads through holes.
Snubber Circuit
RC network suppressing voltage spikes in switching devices.
Solenoid
Electromagnetic coil converting electrical energy into linear motion.
SPI (Serial Peripheral Interface)
Synchronous serial communication protocol.
Static Electricity
Electric charge accumulated on surfaces by friction or induction.
Step Response
Output behavior of a system when input changes suddenly.
Surge Current
Instantaneous large current from switching or power application.
T
Temperature Coefficient
Change in a component’s value per degree of temperature change.
Thermal Runaway
Self-reinforcing heating effect causing component failure.
Thermistor
Resistor whose resistance varies with temperature.
Thermocouple
Temperature sensor generating voltage difference between dissimilar metals.
Thyristor
Four-layer semiconductor that conducts when triggered until current stops.
Tolerance
Allowed deviation from nominal value.
Torque Sensor
Device that measures rotational force.
Transducer
Device converting one form of energy into another (e.g., microphone, sensor).
Transformer
Device transferring electrical energy between circuits via magnetic coupling.
Transient
Short-duration change in voltage or current.
Transistor
Semiconductor device used to amplify or switch signals.
Triac
Bidirectional thyristor controlling AC power.
TTL (Transistor-Transistor Logic)
Digital logic family based on bipolar transistors.
U
UART (Universal Asynchronous Receiver-Transmitter)
Serial interface converting parallel data to serial form and vice versa.
UL (Underwriters Laboratories)
Organization certifying product safety compliance.
USB (Universal Serial Bus)
Standard interface for data and power transfer between electronic devices.
V
VCO (Voltage-Controlled Oscillator)
Oscillator whose output frequency varies with input control voltage.
Vector Signal
Signal with magnitude and phase, used in RF and communication systems.
Voltage (V)
Electrical potential difference between two points.
Voltage Divider
Circuit producing a fraction of input voltage using resistors.
Voltmeter
Instrument for measuring voltage.
W
Watt (W)
Unit of power equal to one joule per second (1 W = 1 V × 1 A).
Waveform
Shape of a signal as a function of time.
Wavelength (λ)
Distance between successive points of equal phase in a wave.
Wheatstone Bridge
Resistive network for precise measurement of unknown resistance.
Wire Gauge (AWG)
Standard for wire diameter; smaller numbers indicate thicker wire.
X
XOR Gate (Exclusive OR)
Logic gate outputting HIGH when inputs differ.
X-Ray Inspection
Non-destructive imaging used to verify solder joints and internal PCB layers.
Y
Y-Parameter
Admittance parameters used in small-signal network analysis.
Yield
Percentage of products meeting all quality standards after production.
Z
Zener Diode
Diode designed to conduct in reverse once voltage exceeds breakdown value.
Zero Crossing Detector
Circuit detecting when AC signal passes through zero voltage.
Zero Sequence Current
Current component flowing equally in all phases during fault conditions.
ZIF Socket (Zero Insertion Force)
Socket allowing IC insertion without mechanical force.
Z-Transform
Mathematical tool for analyzing discrete-time signals and systems.
Notes from PCBasic
PCBasic adheres to IPC, IEC, and ISO standards for terminology and process interpretation.
Our glossary aims to unify communication among design, production, and QA teams globally.
When uncertain about a term in your datasheet, BOM, or Gerber notes, contact your PCBasic engineering representative —
we’ll clarify and ensure your project is interpreted correctly before fabrication or assembly.
