ECE 1 Flashcards
Two-electrode vacuum tube
Introduced by thomas edison and john ambrose fleming in 1904
Thomas alva edison
The inventor of the first practical incandescent light bulb
Jack kilby
Invented the integrated circuit, paving the way for the miniaturization of early
microdevices
Integrated circuit
A complex combination of several kinds of devices on a common base, called
substrate
Atom
The smallest particle of an element that possesses the unique characteristics of that
element
Bohr model
According to this atoms have a planetary type of structure that consists of a central
nucleus surrounded by orbiting electrons
Neils bohr
Creator of the bohr model
Protons
Positively charged particles
Neutrons
Uncharged particles
Electrons
Negatively charged particles
Free electrons
Electrons dislodged from the outer shell of an atom. Are also called condcution
electrons
Insulators
Electric charges do not flow freely in this material
Conductors
Materials that permit electrons to flow freely from particle to particle. They have
positive temperature coefficient
Semiconductors
Solids whose conductivity lies between conductivity of conductors and insulators.
They show the reduction of resistance with the increase in temperature. They have
negative temperature coefficient
Single crystal
Has a repetitive crystal structure
Compound
Constructed of two or more semiconductor materials of different atomic structures
Silicon
The most commonly used semiconductor
Band gap
The difference in energy between the valence band and the conduction band. This is
the amount of energy that a valence electron must have in order to jump from the
valence band to the conduction band.
Convalant bond
The bonding of atoms strengthened by the sharing of electrons
Intrinsic semiconductor
A semiconductor material that has been carefully refined to reduce the number of
impurities to a very low level
Doping
A process of adding impurities to pure semiconductor material to provide positive
and negative charges
Atoms with 5 valence electrons or pentavalent are:
Arsenic (as)
Phosphorus (p)
Bismuth (bi)
Antimony (sb)
Atoms with 3 valence electrons or tetravalent are:
Boron (b)
Indium (in)
Gallium (ga)
Hole
The resulting vacancy in an atom
Semiconductor diode
Is an electronic component created by joining an n-type material with a p-type
material
Depletion region
Region of uncovered positive and negative ions
Diode
A semiconductor device with a single pn junction that conducts current in only one
direction. Made from a small piece of semiconductor material usually silicon
Anode
P region of a diode
Cathode
N region of a diode
No bias
No applied voltage across the diode
Forward bias
Established by applying the positive potential to the n-type material and the negative
terminal is connected to the p-type material
Reverse bias
Established by applying external potential v volts across the p-n junctions
Reverse breakdown
Also called avalanche breakdown and zener breakdown. The external reverse-bias
voltage is increased to a value
Ideal diode model
A perfect two-state device that exhibits zero impedance when forward biased and
infinite impedance when reversed biased
Dc resistance
Is determined by the ratio of the diode voltage and current at the point of interest
and is not sensitive to the shape of the curve
Ac resistance
Is sensitive to the shape of the curve in the region of interest and decreases for
higher levels of diode current or voltage
Load line analysis
The intersection of the characteristic curve of the diode and the load lineThe intersection of the characteristic curve of the diode and the load line
And gate
Has two or more inputs and only one output
Or gate
Has two or more inputs and only one output
Rectification
Process of converting an ac signal into a dc signal
Rectifiers
Are used in power supplies to convert ac voltages to dc voltages
Transformer
Changes ac voltages based on the turns ratio between the primary and secondary
Filter
Eliminates the fluctuations in the rectified voltage and produces a relatively smooth
dc voltage
Regulator
A circuit that maintains a constant dc voltage for
Variations in the input line voltage or in the load
The simplest rectifier circuit
Half wave rectifier
Have the ability to “clip” Off a portion of the input signal without distorting the
remaining part of the alternating waveform
Clippers
Is one where the diode is in series with the load
Series clipper
Is one where the diode is in parallel with the load
Parallel clipper
A network constructed of a diode, resistor, and a capacitor shifts a waveform to a
different dc level without changing the apprearance of the applied signal
Clamper
Are employed to maintain a relatively low transformer peak voltage while stepping
up the peak output voltage to two, three, four, or more times the peak rectified
voltage
Voltage multipliers
