- DAC
Abbreviation for "digital to analog converter."
- damping
- Reduction in magnitude of oscillation due to energy being
dissipated as heat.
- darlington pair
- An amplifier consisting of two bipolar junction transistors
with their collectors connected together and the emitter of one
connected to the base of the other. Circuit has an extremely high
current gain and input impedance.
- DC
- Abbreviation for "direct current".
- DC load line
- A graph representing all possible combinations of voltage and
current for a given load resistor in an amplifier.
- DC offset
- The change in input voltage required to produce a zero output
voltage when no signal is applied to an amplifier.
- DC power supply
- Any source of DC power for electrical equipment.
- dead short
- Short circuit having zero resistance.
- decade
- A frequency factor of ten.
- decibel
- (dB) a logarithmic representation of gain or loss.
- degenerative feedback
- Also called negative feedback. A portion of the output of an
amplifier is inverted and connected back to the input. This controls the
gain of the amplifier and reduces distortion and noise.
- delay time
- The time for collector current to reach 10% of its maximum
value in a BJT switching circuit.
- depletion region
- Thre area surrounding a pn junction that is depleted of
carriers.
- depletion mode
- In a FET, an operating mode where reverse gate-source voltage
is used to deplete the channel of free carriers. This reduces the size
of the channel and increases its resistance.
- depletion-mode MOSFET
- A MOSFET designed to operate in either depletion mode or
enhancement mode.
- device
- A component or part.
- diac
- A two terminal bidirectional thyristor. Has a symmetrical
switching mode.
- dielectric
- Insulating material between two plates where an electrostatic
field exists.
- dialectric constant
- Peoperty of a material that determines how much electrostatic
energy can be stored per unit volume when unit voltage is applied.
- dialectric strength
- The maximum voltage an insulating material can withstand
without breaking down.
- differential amplifier
- An amplifier in which the output is in proportion to the
differences between voltages applied to its two inputs.
- differentiator
- A circuit in which the output voltage is in proportion to the
rate of change of the input voltage. A high pass RC circuit.
- diffusion
- Tendency of conduction band electrons to wander across a pn
junction to combine with valence band holes.
- digital
- Relating to devices or circuits that have outputs of only two
discrete levels. Examples: 0 or 1, high or low, on or off, true or false
etc.
- diode
- A two terminal device that conducts in only one direction.
- DIP
- Abbreviation for "dual in line package."
- direct coupling
- Where the output of an amplifier is connected directly to the
input of another amplifier or to a load. Also known as DC coupling
because DC signals are not blocked.
- direct current
- Current that flows in only one direction.
- discharge
- Release of energy stored in either a battery or a capacitor.
- discrete component
- Package containing only a single component as opposed to an
integrated circuit containg many components in a single package.
- dissipation
- Release of electrical energy in the form of heat.
- distortion
- An undesired change in a waveform or signal.
- distributed capacitance
- Any capacitance other than that within a capacitor. For
example, the capacitance between adjacent turns of wire in a coil.
- distributed inductance
- Any inductance other than that within an inductor. Example
inductance in any conductor.
- domain
- A moveable magnetized area in a magnetized material. Also
known as magnetic domain.
- donor atoms
- Pentavalent atoms that give up electrons to the conduction
band in an N type semiconductor material.
- doping
- The process of adding impurity atoms to intrinsic (pure)
silicon or germanium to improve the conductivity of the semiconductor
material.
- dot convention
- Standard used with transformer symbols to indicate whether
the secondary voltage is in phase or out of phase with the primary
voltage.
- drift
- A problem that can develop in tuned amplifiers when the
frequency of the tuned circuit changes due to temperature or component
aging.
- dropping resistor
- Resistor whose value has been chosen to drop or develop a
given voltage.
- dry cell
- DC voltage generating chemical cell using a non liquid
(paste) electrolyte.
- dual in-line package
- Integrated circuit package having two rows of connecting
pins.
- dual trace oscilloscope
- Oscilloscope that can simultaneously display two signals.
- dynamic
- Relating to conditions that are changing or in motion.
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