Lecture 7: Electronics

Semiconductors

Materials with electrical conducting properties between conductors and insulators, used in modern electronics.

Doping

The addition of impurities to a semiconductor to change its electrical properties.

n-type semiconductors

Semiconductors doped with donor impurities, having an excess of negative charge carriers.

p-type semiconductors

Semiconductors doped with acceptor impurities, having positive charge carriers.

p-n junction

A junction formed where n-type and p-type semiconductors connect.

Depletion region

The area in a semiconductor junction that has no charge carriers.

Forward Biased

Condition when a diode allows current to flow freely.

Reverse Biased

Condition when a diode blocks current flow, except for a small leakage.

Rectification

The process of converting alternating current (a.c.) to direct current (d.c.).

Capacitance

The ability of a capacitor to store charge, measured in farads.

Energy stored in a capacitor

Calculated by the equation E = ½ QV or E = ½ CV².

Capacitors in Series

The total capacitance in a series circuit is found using 1/Ce = 1/C1 + 1/C2 + 1/C3.

Capacitors in Parallel

Total capacitance in a parallel circuit is the sum of all capacitances: Ce = C1 + C2 + C3.

Transistor

An electronic component that can act as a switch or amplifier in circuits.

Logic Gates

Circuits that use transistors as high-speed switches, producing specific electrical outputs.

NOT Gate

A logic gate that outputs high if the input is low, and vice versa.

AND Gate

Outputs high only when both inputs are high.

OR Gate

Outputs low only when both inputs are low.

NAND Gate

Outputs low only when both inputs are high.

NOR Gate

Outputs high only when both inputs are low.

Integrated Circuits (ICs)

Circuits consisting of multiple electronic components on a single silicon chip.

Microprocessor

A miniature version of the CPU of a digital computer, controlling various functions.

Acoustic Coupling

Using sound waves for data transmission between devices.

Logic Level 1

Represents high voltage output in logic circuits.

Logic Level 0

Represents low voltage output in logic circuits.