Electronic Devices and Basic Circuits Flashcards

Vocabulary flashcards covering basic semiconductor concepts, PN junction biasing, junction breakdown mechanisms, and ideal diode operation.

Electrical Systems

Engineering systems focused on the generation, transmission, and distribution of electrical power, as well as the design of power plants, electrical grids, motors, generators, and transformers.

Electronics Systems

Engineering systems focused on the application of electrical devices using active components such as transistors, diodes, and integrated circuits to control and process electrical signals in computers, communications, microchips, medical equipment, and sensors.

Microelectronics

The field of electronics dealing with extremely small electronic components and integrated circuits, allowing millions of transistors to be integrated onto tiny semiconductor chips.

Vacuum Tube

An early electronic valve that permits current flow in one direction by heating a cathode to emit electrons captured by an unheated anode, while blocking reverse current.

Solid-State Electronics

Electronic technology that controls the flow of electrical current through solid semiconductor materials rather than through a vacuum.

Semiconductor

A material whose electrical conductivity lies between that of conductors and insulators, such as silicon, germanium, carbon, or gallium arsenide.

Intrinsic State

The pure, undoped state of a semiconductor crystal in which no impurity atoms have been added.

Intrinsic Silicon Crystal at $0\, \text{K}$

A state in which all valence electrons are locked in shared covalent bonds around silicon atomic cores of charge $+4q$, leaving zero free electrons available for electrical conduction.

Generation and Recombination

The processes in semiconductors where thermal energy breaks covalent bonds to create free electron-hole pairs (generation), and free electrons fall back into holes (recombination).

Doping

The process of intentionally adding impurity atoms to an intrinsic semiconductor crystal to alter its charge carrier concentrations.

N-Type Doping

Doping an intrinsic semiconductor with pentavalent impurity donor atoms to produce a majority of free electrons ($n_e \gg n_h$).

P-Type Doping

Doping an intrinsic semiconductor with trivalent impurity acceptor atoms to produce a majority of holes ($n_h \gg n_e$).

Depletion Region

The region around a PN junction depleted of mobile charge carriers, containing uncovered fixed donor and acceptor ions that form an internal electric field.

Diffusion Current ($I_{\text{diffusion}}$)

The electric current across a PN junction produced by the movement of majority charge carriers diffusing down their concentration gradient.

Drift Current ($I_{\text{drift}}$)

The electric current across a PN junction produced by minority charge carriers swept across the depletion region by the built-in electric field.

Built-in Potential Barrier ($V_0$)

The internal voltage established across an open-circuit PN junction depletion region that opposes majority carrier diffusion until equilibrium is reached where $I_{\text{diffusion}} + I_{\text{drift}} = 0$.

Diode Forward Bias

The condition where an external positive voltage applied to the P-type side relative to the N-type side lowers the potential barrier and narrows the depletion region, allowing significant majority carrier diffusion current.

Diode Reverse Bias

The condition where an external positive voltage applied to the N-type side relative to the P-type side widens the depletion region and increases the potential barrier, resulting in only a small minority carrier drift current.

Junction Capacitance ($C_j$)

The voltage-dependent capacitance exhibited by a reverse-biased PN junction, given by $C_j = \frac{C_{j0}}{\sqrt{1 + \frac{V_R}{V_0}}}$ with zero-bias capacitance $C_{j0} = \sqrt{\frac{\epsilon_{Si} q}{2} \frac{N_A N_D}{N_A + N_D} \frac{1}{V_0}}$.

Junction Breakdown

A phenomenon in a reverse-biased PN junction where applying a sufficiently large reverse voltage ($V_{BD}$) causes covalent bonds to break, resulting in a rapid, large increase in reverse current.

Avalanche Breakdown

A junction breakdown mechanism occurring in lightly or moderately doped PN junctions where highly accelerated minority carriers liberate additional electrons through impact ionization in a chain reaction.

Zener Breakdown

A junction breakdown mechanism occurring in heavily doped PN junctions where a strong internal electric field directly pulls electrons out of covalent bonds at reverse voltage $V_Z$.

Ideal Diode

A simplified model of a diode that acts as a perfect two-terminal switch, operating as a short circuit in forward bias and an open circuit in reverse bias.

Ideal Diode Forward Bias (Turned-on Mode)

The operating state of an ideal diode when conducting positive current ($i_D > 0$) with zero voltage drop ($v_D = 0$) and zero internal resistance, acting as a short circuit.

Ideal Diode Reverse Bias (Cut-off Mode)

The operating state of an ideal diode when subjected to negative voltage ($v_D < 0$) with zero current flow ($i_D = 0$) and infinite internal resistance, acting as an open circuit.

Rectifier

A circuit application of diodes that converts an alternating voltage (AC) signal into a single-polarity output signal.

Diode Logic Gates

Digital logic circuits (such as OR and AND gates) constructed using diodes and resistors to implement Boolean operations based on input voltage levels.