ECE TERMS
also known as trivalent and it is the atom that can take an electron
ACCEPTOR ATOM
the smallest particle of an element that retains the properties of that element
ATOM
elements in the periodic table are arranged according to this
ATOMIC NUMBER
multiplication of conduction electrons
AVALANCHE
occurs when VB is > 5V
AVALANCHE BREAKDOWN
necessary because electronic circuits require a constant source of a DC voltage and current to provide power and biasing for proper operation.
FILTERING
escaped valence electron
FREE ELECTRONS
allows unidirectional (one-way) current through the load during the entire 360 of the input cycle, whereas a half-wave rectifier allows current through the load only during one-half of the cycle.
FULL-WAVE RECTIFIER
most frequently used in the construction of electronic devices
Ge, Si, and GaAs
The process of removing one-half the input signal to establish a dc level
HALF-WAVE RECTIFICATION
the condition that essentially prevents current through the diode.
REVERSE BIAS
an indication of the effectiveness of the filter
RIPPLE FACTOR
variation in the capacitor voltage due to the charging and discharging
RIPPLE VOLTAGE
changes ac voltages based on the turns ratio between the primary and secondary
TRANSFORMER
often used to couple the ac input voltage from the source to the rectifier as shown in the figure.
TRANSFORMER
- contribute to the sharp change in the characteristic of a diode - occurs because there is a strong electric field in the region of the junction that can disrupt the bonding forces within the atom and "generate" carriers
ZENER BREAKDOWN
occurs when VB is < 5V
ZENER BREAKDOWN
a silicon pn junction device that is designed for operation in the reverse- breakdown region
ZENER DIODE
diodes that employ the unique portion of the characteristic of a p-n junction
ZENER DIODES
the sharp change in the characteristic at any level
ZENER REGION
a type of full-wave rectifier that uses two diodes connected to the secondary of a center-tapped transformer.
CENTER-TAPPED RECTIFIER
they have a capacitor connected directly from input to output with a resistive element in parallel with the output signal.
CLAMPING NETWORKS
diodes were discovered
1939
transistors were discovered
1947
first silicon transistor was introduced
1954
- converts 220V, 60 Hz ac voltage available at wall outlets into a constant dc voltage - generally the ac input line voltage is stepped down to a lower ac voltage with a transformer
DC POWER SUPPLY
- the region where two layers of positive and negative ions form - a very thin layer compared to the p-region and n-region
DEPLETION REGION
the capacitance involved when excess charge builds up a potential difference across the junction, which in turn creates a capacitance-like effect
DIFFUSION CAPACITANCE
• It was formed when a block of silicon was doped part of it with trivalent and other part with a pentavalent impurity. • is a device that conducts current only in one direction.
DIODE
- to bias a diode, you apply a dc voltage across it
DIODE BIASING
also known as pentavalent and it is the atom that gives up electron
DONOR ATOM
the process that increases the number of current carriers (electrons or holes)
DOPING
the resistance changes as you move along the V-I curve
DYNAMIC OR AC RESISTANCE
forces between opposite charges that form a field of charges
ELECTRIC FIELD
This movement of free electrons is one type of current in a semiconductive material
ELECTRON CURRENT
flow of free electrons
ELECTRON CURRENT
the hole created for every electron raised to conduction band by external energy
ELECTRON-HOLE PAIR
This is the amount of energy that a valence electron must have in order to jump from the valence band to the conduction band.
ENERGY GAP OR BAND GAP
eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage
FILTER
parallel variety has the diode in a branch parallel to the load.
PARALLEL CLIPPERS
forms when a piece of intrinsic silicon is doped so that part is n-type and the other part is p-type
PN JUNCTION
the process when electrons in conduction band loses energy an it goes back to the hole
RECOMBINATION
converts the ac input voltage to a pulsating dc voltage, called a half-wave rectified voltage
RECTIFIER
a circuit that maintains a constant dc voltage for variations in the input line voltage or in the load
REGULATOR
extremely small current that exists in reverse bias caused by the minority carriers in the n and p regions that are produced by the thermally generated electron-hole pairs
REVERSE CURRENT
- also known as reverse current - the current that exists under reverse-bias condition
REVERSE SATURATION CURRENT (Is)
undesirable, thus the smaller the ripple the better the filtering action is.
RIPPLE
materials that is between conductors and insulators in its ability to conduct electrical current
SEMICONDUCTORS
series configuration is defined as one where the diode is in series with the load.
SERIES CLIPPERS
the amount of voltage required to move an electron through the electric field
BARRIER POTENTIAL
it refers to the use of a DC voltage to establish certain operating conditions for an electronic device.
BIAS
if the external reverse bias voltage is increased to this value, the reverse current will drastically increase
BREAKDOWN VOLTAGE
a network constructed of a diode, a resistor, and a capacitor that shifts a waveform to a different dc level without changing the appearance of the applied signal.
CLAMPER
- also known as diode limiters - networks that employ diodes to "clip" away a portion of an input signal without distorting the remaining part of the applied waveform.
CLIPPERS
constructed of two or more semiconductor materials of different atomic structures. Example: GaAs, CdS, GaN, GaAsP
COMPOUND
materials that easily conduct current
CONDUCTORS
Bonding of atoms strengthened by the sharing of electrons.
COVALENT BONDING
materials that does not conduct electrical current under normal condition
INSULATORS
process of losing a valence electron
IONIZATION
- used to model the voltage-current (V-I) characteristic of a semiconductor diode - describes the relationship between the current flowing through the diode and the voltage across it
SHOCKLEY'S DIODE EQUATION
• have improved temperature sensitivity • One of the most abundant materials on earth • Has the benefit of years of development • Is the leading semiconductor materials for electronic components and ICs
SILICON
typical values of barrier potential at 25 deg C
SILICON = 0.7 V GERMANIUM = 0.3 V
have repetitive crystal structure ex: Ge and Si
SINGLE CRYSTAL
specifies how much change occurs in the output voltage for a given change in the input voltage
LINE REGULATION
used to analyze diode circuit using its actual characteristics.
LOAD LINE ANALYSIS
specifies how much change occurs in the output voltage over a certain range of load current values, usually from minimum current (no load) to maximum current (full load)
LOAD REGULATION
two types of semiconductor
SINGLE CRYSTAL COMPOUND
Two categories of impurities
N-TYPE P-TYPE
electrons on the valence shell
VALENCE ELECTRON
the outermost shell of an atom
VALENCE SHELL
power supplies is usually done with integrated circuit voltage regulators
VOLTAGE REGULATION
- prevents changes in the filtered DC voltage due to variations in input voltage or load - connected to the output of a filtered rectifier and maintains a constant output voltage (or current) despite changes in the input, the load current, or the temperature.
VOLTAGE REGULATOR