BASIC ELECTRONICS AND DIGITAL ELECTRONICS - Vocabulary Flashcards

A comprehensive set of vocabulary terms and concise definitions drawn from the lecture notes on basic and digital electronics.

N-type semiconductor

Semiconductor doped with donor atoms (Group V) to add extra electrons; electrons are the majority carriers; negative-type.

P-type semiconductor

Semiconductor doped with acceptor atoms (Group III) to create holes; holes are the majority carriers; positive-type.

Doping

Introduction of impurities into a semiconductor to modify its electrical properties.

Majority carriers

The dominant charge carriers in a doped semiconductor (electrons in N-type, holes in P-type).

Minority carriers

The less abundant charge carriers (holes in N-type, electrons in P-type).

Donor dopants

Impurities (Group V) that donate electrons to the host material (e.g., P, As in Si).

Acceptor dopants

Impurities (Group III) that create holes by accepting electrons (e.g., B, Ga in Si).

PN junction

Interface between N-type and P-type regions; basis for diodes, transistors, and solar cells.

Depletion region

Charge-free region at a PN junction formed by diffusion and electric fields.

Diode

Two-terminal device that conducts current mainly in one direction.

Zener diode

A diode designed to operate in reverse breakdown for voltage regulation.

Zener voltage (Vz)

Reverse voltage at which the Zener diode maintains a constant voltage.

Zener breakdown

Controlled conduction in reverse bias that clamps the voltage.

Avalanche breakdown

High-voltage breakdown mechanism due to impact ionization.

Forward voltage drop (diode)

Voltage drop across a diode when it conducts in forward bias (≈0.7V for silicon).

Dynamic resistance (Rz)

Resistance of a Zener diode in its breakdown region.

Zener diode symbol

Diode symbol variant with a Zener-style notch near the cathode.

Voltage regulation (Zener)

Using a Zener to keep output voltage constant despite changes in input/load.

Reference voltage

Stable voltage used as a reference in circuits; Zener diodes often serve this role.

Clipping/Clamping

Circuits that limit or fix voltage levels using diodes/Zeners.

Surge protection

Protecting devices from overvoltage by clamping spikes.

Zener regulator example

A 5.1 V Zener clamps the output to 5.1 V when Vin exceeds that value.

NPN transistor

Three-layer device: N-P-N; emitter and collector are N-type; base is P-type.

PNP transistor

Three-layer device: P-N-P; emitter is P-type; base N-type; collector P-type.

Emitter (NPN)

Negative-side emitter in NPN; typically near ground in circuits.

Collector (NPN)

Positive-side terminal that collects carriers in NPN; connected to supply.

Base (NPN)

Control terminal; small base current modulates larger collector-emitter current.

Base current

Small current that controls the larger current between collector and emitter.

Collector current

Main current in a transistor, controlled by base current.

Emitter current

Total current leaving the emitter (IE = IB + I_C).

NPN symbol (arrow)

Arrow on NPN symbol points outward (from base to emitter).

PNP symbol (arrow)

Arrow on PNP symbol points inward (from emitter to base).

Common Emitter (CE) configuration

Emitter is common to input and output; high gain; 180° phase shift.

Common Collector (CC) configuration

Emitter follower; high input impedance, low output impedance; no voltage gain.

Common Base (CB) configuration

Base is common; high voltage gain, low current gain; low input impedance.

NPN applications

Switching circuits and signal amplification; widely used in electronics.

PNP applications

Used for high-side switching and similar amplification tasks.

Transistor base current

Small current that controls larger collector-emitter current.

BJTs (Bipolar Junction Transistors)

Transistors where current control involves both electron and hole carriers.

FET

Field-Effect Transistor; current controlled by gate voltage affecting a channel.

Gate (FET)

Terminal that modulates the conductivity of the channel.

Source (FET)

Terminal where carriers enter the channel.

Drain (FET)

Terminal where carriers leave the channel.

Channel (FET)

Conduction path between source and drain; can be N-type or P-type.

N-channel MOSFET (NMOS)

Channel is N-type; conducts with positive gate voltage to form a channel.

P-channel MOSFET (PMOS)

Channel is P-type; conducts with negative gate voltage to form a channel.

Junction Field-Effect Transistor (JFET)

FET with reverse-biased gate; depletion region controls current; normally on.

JFET advantages

High input impedance, low noise; common for amplification.

MOSFET advantages

Very high input impedance, low power; scalable for integrated circuits.

MOSFET disadvantages

Temperature sensitivity and vulnerability to static discharge.

LED (Light Emitting Diode)

Semiconductor device that emits light when forward biased.

Energy band gap (LED color)

Band gap determines photon color; GaAsP (red), GaN (blue) examples.

GaAsP

Gallium Arsenide Phosphide; material used for red/orange LEDs.

GaN

Gallium Nitride; material used for blue/green LEDs.

LED advantages

High efficiency, long life, instant on, compact, low power.

SCR (Silicon Controlled Rectifier)

Four-layer PNPN thyristor with a gate; latches on after triggering.

SCR terminals

Anode, Cathode, Gate; gate triggers conduction from anode to cathode.

SCR operation

Forward-blocking state; gate trigger turns device on; current sustains until zero.

Latch-up (SCR)

SCR remains conducting after gate signal removal.

SCR applications

Power control (phase control), rectifiers, and high-power switching.

Opto-coupler

Device that transfers signals via light to provide electrical isolation.

Opto-coupler components

Input LED and output photodetector; optical isolation between sides.

Photodiode

Light-sensitive diode; generates current when illuminated; reverse-biased operation common.

Photodiode modes

Photovoltaic (solar cell) and photoconductive (reverse-biased) modes.

APD

Avalanche Photodiode; photodiode with internal gain via avalanche multiplication.

Phototransistor

Light-sensitive transistor; provides current amplification controlled by light.

Photodetector parameters

Responsivity, Quantum efficiency, Dark current, Bandwidth.

CRO

Cathode Ray Oscilloscope; visualizes waveforms on a CRT.

555 Timer

IC that can operate in monostable, astable, and bistable modes for timing.

555 timer operation

Internal resistor-capacitor network with comparators sets timing via external R and C.

Oscillator

Circuit that generates periodic signals (sine, square, triangle) without an external input.

LC oscillator

Inductor-capacitor tank; Colpitts and Hartley variants for RF sine waves.

RC oscillator

Resistor-capacitor network; Phase Shift or Wien Bridge for RC sine waves.

Crystal oscillator

Crystal-based oscillator using quartz for high stability frequency control.

VCO

Voltage-Controlled Oscillator; frequency set by control voltage.

Wien Bridge oscillator

RC oscillator using Wien bridge; stable sine wave output.

Colpitts oscillator

LC oscillator with feedback via two capacitors in the tank.

Hartley oscillator

LC oscillator using tapped inductor for feedback.

Relaxation oscillator

Generates non-sinusoidal waves by charging/discharging a capacitor.

Quartz crystal oscillator

Crystal-based oscillator with high stability for clocks and radios.

Ring oscillator

Digital oscillator formed by an odd number of inverters in a feedback loop.

Binary-coded decimal (BCD)

Decimal digits encoded as four-bit binary equivalents.

Gray code

Binary code where successive values differ by only one bit.

A/D converter (ADC)

Converts analog signals to digital data; characterized by resolution and sampling rate.

D/A converter (DAC)

Converts digital data to analog voltage/current; characterized by resolution and output range.

Resolution (ADC/DAC)

Number of distinct levels representable by the converter (bits).

Sampling rate

Frequency at which the analog signal is sampled (samples per second).

SAR ADC

Successive Approximation Register ADC; good speed and resolution.

Delta-Sigma ADC

High-accuracy ADC using oversampling and noise shaping.

Binary-weighted DAC

DAC using resistors weighted by powers of two for each bit.

R-2R ladder DAC

DAC using a repeating R-2R resistor network for scalable resolution.

Boolean algebra

Algebra of logic using binary variables and operations AND, OR, NOT.

Boolean variables

Variables taking values 0 or 1.

Laws: Identity

A·1 = A, A + 0 = A.

Laws: Null

A·0 = 0, A + 1 = 1.

Laws: Complement

A·¬A = 0, A + ¬A = 1.

Laws: Idempotent

A·A = A, A + A = A.

Laws: Distributive

A·(B+C) = A·B + A·C; A+(B·C) = (A+B)·(A+C).

Truth table

Tabular representation of output for all input combinations.

Mealy machine

Finite state machine where outputs depend on state and inputs.