Flashcards
Bipolar Transistors (Mod. 4 Sect. 3 Part 1)
Cards in this deck (62)
- 1A _____ is a three-terminal, solid-state semiconductor that's used to control the flow of electrons in a circuit.transistor
- 2The word "transistor" is a shortened form of "____________", and this is a good description of what a transistor does in a circuit.current-transferring resistor
- 3A transistor is made from ____ layers of doped semiconductor crystals (usually silicon or germanium).three
- 4The three layers in a transistor can be arranged in either ___ formation or ___ formation.NPN, PNP
- 5An ___ transistor contains a thin layer of p-type material sandwiched between two N-type layers.NPN
- 6The ___ transistor contains a thin layer of N-type material sandwiched between two P-type layers.PNP
- 7The piece of material/crystal that's grown to make a transistor is called an ____.ingot
- 8The two end sections of a transistor are called the _____ and the _____. The center section is called the _____.collector, emitter, base
- 9Because transistors have three sections, they have two PN junctions. This is called a _____ transistor.bipolar
- 10The junction between the emitter and base is called the ________ junction (____ junction).emitter-base, E-B
- 11The junction between the base and collector is called the ________ junction (___ junction).base-collector, B-C
- 12N-type (negative) materials contain excess ____, and P-type (positive) materials contain excess ____.electrons, holes
- 13Applying the needed DC potentials to the electrodes of a transistor in order to "push" the transistor into conduction is called _____.biasing
- 14In order to get a bipolar transistor into operation, a _____ must be applied to both the base and collector.voltage
- 15Because a small change in the base current produces a large change in collector current, bipolar transistors can _____ (increase) signals.amplify
- 16Changes in base and collector current are the basic principle behind transistor amplifier operation.no answer, just remember dis
- 17In a bipolar transistor, the amount of signal amplification can be altered by controlling the amount of _______ (voltage) into the base.electron flow
- 18The control of the amount of current or voltage that enters the base is called _____.biasing
- 19The ______ voltage is the voltage applied to the base that will push the transistor into conduction.base voltage
- 20The _______ current is the current applied to the base that will determine the collector current.base bias
- 21The _____ of a transistor is the point at which the transistor starts to conduct.bias point
- 22When no voltage at all is connected to the base, the base bias is ____.zero
aka "zero base bias" - 23If you continue raising the base current, a point will be reached where the collector current levels off. This is called the _____ point. (the transistor is conducting as much as it can)saturation
- 24When too much current is delivered to a transistor, it is said to be operating in _______. This causes inefficiency in a circuit, and the transistor could be destroyed.overdrive
- 25When only a DC signal is connected to a transistor, it's said to be in the _____ mode of operation.static
- 26When only an AC signal is connected to a transistor, it's said to be in the _____ mode of operation.dynamic
- 27__________ biasing is one method used to obtain a base bias voltage in a transistor.power supply
- 28________ biasing is the most common method of biasing used in transistor circuits.voltage divider
- 29When a transistor is voltage divider biased, there's an additional resistor that's called an _________ resistor. This resistor helps prevent thermal runaway.emitter stabilization
(aka temperature stabilization) - 30________ is an upward spiral of increasing heat and current in a transistor.Thermal runaway
- 31______ operation is a transistor biased so that only half of the input waveform gets reproduced.Class-B
- 32In an ___________ (___) circuit, a radio signal is delivered to an amplifier. The output of that amplifier goes to several additional amplifiers. At some point in the receiver, part of the signal gets rectified into DC voltage. This voltage is then fed back into the first amplifier and used for biasing. This circuit prevent changes in the strength of the radio input signal changing the volume of the output signal.automatic volume control (AVC)
- 33If the bias voltage is increased above the requirement for maximum, the gain decreases. This is called _____ AVC.forward
- 34If the bias voltage is decreased below the requirement for maximum, the gain is decreased. This is called _____ AVC.reverse
- 35In a _____ amplifier, the positive and negative swings of the output current are amplified equally.linear
- 36In a _____ amplifier, certain portions of the output current are more amplified than others.nonlinear
- 37_____ reactance is is reactance due to the presence of capacitance in an AC circuit.Capacitive
- 38_____ reactance is the part of the reactance of an AC circuit that's due to inductance.Inductive
- 39When both reactances and resistances are present in an AC circuit, the total opposition to the flow of AC current is called _____.impedance
- 40_____ is represented by the symbol Z and is measured in ohms.Impedance
- 41When the values of internal impedance and the external impedance are equal, and at the same time, the external reactance is equal to the internal reactance. This is a special situation called _____.resonance
- 42Resonance is also called _________.impedance match
- 43_____ impedance is the amount of impedance you would measure at the output terminals.Output
- 44_____ impedance is the amount of impedance that you would measure at the input terminals.Input
- 45The term ____ refers to an amplifier's ability to increase the amplitude of a weak signal.gain
- 46In a transistor, the _____ terminal is the third connection and is common to both the input and output terminals.common
- 47There's 3 possible configurations for an NPN amplifier circuit: _________ amplifiers, ________ amplifiers, and ________ amplifiers.common-emitter, common-collector, common-base
- 48The behavior of any amplifier depends directly on which terminal is used as the _____ connection.common
- 49The _______ amplifier is the most commonly used configuration. The input signal is delivered to the base, and the output signal is taken from the collector.common-emitter
- 50In a ________ amplifier configuration, the input signal is delivered to the base and the output signal is taken from the emitter.common-collector
(aka emitter follower) - 51In a ________ amplifier configuration, the input signal is delivered to the emitter and the output signal is taken from the collector.common-base
- 52A transistor's _____ are fixed specifications that tell you what the transistor is capable of doing.parameters
- 53A transistors current gain is indicated by two related specifications: ____ and ____. These two values can tell you how well a bipolar transistor performs as an amplifier.alpha, beta
- 54The best way to evaluate a transistor for replacement is to determine its ____ value.beta
- 55In the normal operation of bipolar transistors, about ___ percent of the charge carriers pass through the base lead and about ___ percent pass through the collector lead.2, 98
- 56The sum of currents at any junction must be ___.zero
- 57In a bipolar transistor, the voltage of the ____ lead is considered to be 0 V with respect to the _____ lead and the _____ lead.emitter, base, collector
- 58Bipolar transistors are usually made from doped crystals of ______ and _____.silicon, germanium
- 59The ________ is the voltage applied to the base that will push a transistor into conduction.base bias voltage
- 60Thermal runaway is prevented by connecting a resistor to the ______ lead.emitter
- 61If the base voltage on an NPN transistor becomes more positive than the collector volt age, the transistor will be _____.destroyed
- 62The opposition that a capacitor offers to the flow of AC current is called __________.capacitive reactance