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Bipolar Junction Transistors
- current controlled
- use both holes and electrons as carriers
- have three terminals called the emitter, base, and collector
- only available in one mode of operation
Field-Effect Transistors
- voltage controlled (like vacuum tubes)
- use either holes or electrons as carriers, not both
- have three or four terminals called the source, gate, drain and sometimes substrate
- available in either enhancement mode or depletion mode of operation
What else can I help you with?
What jobs can a transistor do when combined with the CPU?
The modern CPU (typically inside a microprocessor IC) is built of billions of transistors (typically complementary MOSFETs). The CPUs of the late 1960s were built of tens of thousands to hundreds of thousands of transistors inside several hundred MSI ICs (typical silicon NPN BJTs). The CPUs of the late 1950s to early 1960s were built of thousands to tens of thousands of discrete transistors (typically germanium BJTs, gradually transitioning silicon BJTs). The CPUs of the early 1950s did not use transistors, they were built of hundreds to tens of thousands of vacuum tubes.
Difference between de mosfet and e mosfet?
The basic difference is between JFET and enhanced MOSFET,although the construction of JFET and depletion MOSFET is different but their most of the characteridtics are same,i.e shockly equation can be applied on both of them,but in JFET we cant give to gate voltage, the +ve value,because it does not works, but in depletion we can give,but some limited +ve value. Now enhanced MOSFET is different,shockly equation cant be applied.The transfer characteristics are purely in +ve Vg region. i.e for E-MOSFET Vg should be > 0,for its proper function.
What is relation between IC AND IB?
IC (collector current) and IB (base current) are related in a bipolar junction transistor (BJT) through the transistor's current gain, denoted as β (beta). The relationship can be expressed as IC = β * IB, meaning that the collector current is a multiple of the base current, where β typically ranges from 20 to 1000 for most BJTs. This relationship highlights the transistor's ability to amplify current, making it a crucial component in electronic circuits.
What is difference between bjt and scr?
BJT is nothing but the addition of two PN junction diodes. There are two types of BJT= P-N-P or N-P-N P-N N-P + or + N-P = P-N-P P-N =N-P-N SCR is a thyristor which is made adding two BJTs. Of course they are made of sillicon. Exempli gratia: P-N-P + + N-P-N = P-N-P-N comparison between scr bjt and mosfet Check the related link for further information.
Why ujt is not used as amplifier?
The UJT (Uni-Junction Transistor) is not typically used as an amplifier because it does not have the necessary characteristics for linear amplification. Its operation is primarily based on negative resistance and it is designed for triggering applications, such as in relaxation oscillators and timing circuits. The UJT has a limited control over output current, making it unsuitable for applications that require linear gain. Instead, BJTs and FETs are preferred for amplification due to their ability to provide a stable and linear relationship between input and output signals.
What are the main differences between FETs and BJTs in terms of input impedance?
FET has very high input impedanceBJT has very low input impedance
Is the collector current dependent on colllector- emitter voltage in BJTs?
No. For BJTs, they have a natural amplification, B, of current between the base current to collector current. In rough calculations, I've often used 50. So applying 20uA of current to the base of a BJT should cause 1mA of current to flow through the collector (assuming base, collector, and emitter resistors are sized appropriately so this is not limitted). The emitter will see the base current + the collector current.
What are the two main types of transistors?
The two main types of transistors are bipolar junction transistors (BJTs) and field-effect transistors (FETs). BJTs operate by controlling the flow of current via two types - NPN and PNP. FETs control current flow using an electrical field, with types including MOSFETs and JFETs.
What is TTL logic?
TTL Logic Circuits - "Transistor Transistor Logic" - are made using BJTs. They operate from +5 Volts. These are available from simple AND, OR, NAND Gates to complex circuits. The voltage levels are INPUT OUTPUT Low (0) < 0.8V <0.4V High (1) >2.0V >2.4V Levels in between are undefined. The outputs are better than the inputs by 0.4V thus offering a noise margin. These are seldom used these days as other logic families have been introduced offering more advantages like, speed, lower power, wider / lower operating voltage, higher fanouts.
What jobs can a transistor do when combined with the CPU?
The modern CPU (typically inside a microprocessor IC) is built of billions of transistors (typically complementary MOSFETs). The CPUs of the late 1960s were built of tens of thousands to hundreds of thousands of transistors inside several hundred MSI ICs (typical silicon NPN BJTs). The CPUs of the late 1950s to early 1960s were built of thousands to tens of thousands of discrete transistors (typically germanium BJTs, gradually transitioning silicon BJTs). The CPUs of the early 1950s did not use transistors, they were built of hundreds to tens of thousands of vacuum tubes.
Difeerence between n-channel and p-channel fet?
The field-effect transistor (FET) is a transistor that relies on an electric field to control the shape and hence the conductivity of a channel of one type of charge carrier in a semiconductor material. FETs are sometimes called unipolar transistors to contrast their single-carrier-type operation with the dual-carrier-type operation of bipolar (junction) transistors (BJT). The concept of the FET predates the BJT, though it was not physically implemented until after BJTs due to the limitations of semiconductor materials and the relative ease of manufacturing BJTs compared to FETs at the time.
Why bjt is a minority carrier device?
Although a small part of the transistor current is due to the flow of majority carriers, most of the transistor current is due to the flow of minority carriers and so BJTs are classified as 'minority-carrier' devices.
Difference between de mosfet and e mosfet?
The basic difference is between JFET and enhanced MOSFET,although the construction of JFET and depletion MOSFET is different but their most of the characteridtics are same,i.e shockly equation can be applied on both of them,but in JFET we cant give to gate voltage, the +ve value,because it does not works, but in depletion we can give,but some limited +ve value. Now enhanced MOSFET is different,shockly equation cant be applied.The transfer characteristics are purely in +ve Vg region. i.e for E-MOSFET Vg should be > 0,for its proper function.
Advantages of fet over bjt?
mainly i will tell ttwo advantages:- 1)in FET "thermal runaway" never occurs but in bjt it occurs easily...thermal runaway means overheating and damage of fet due to different biasing voltages.. 2) since FET is a unipolar device so only one carrier type is required here ,but bjt is a bipolar device .. 3) FET is smaller in size than BJT of same rating. i mean to say that at the place of 10 bjts we can use 90 FETs ..so area cosumption is less
Comparison of FET and BJT?
A: Initially the construction of an FET closely resemble the double diffused bipolar epitaxial transistor Both begins with an n+ substrate n- forming a 4 layer structure. another distinguishing feature is the electrical bonding of the upper most n+ diffusion [source] however with this bonding a parasitic diode in parallel cathode drain to source fortunatelly by virtue the polarity operation is unaffected. All in all FET have higher power, higher voltage rating practically no thermal runaway and a greatly inhibited secondary breakdown characteristics
What are the differences between bi-cmos and cmos technology?
CMOS circuits utilize complementary MOSFETs, i.e; NMOS and PMOS devices together in various patterns to create functional blocks like AND or OR gates. However the problem with these types of CMOS circuits is that they are inherently low power circuits. They cannot handle large currents. So when your block needs to have a large fan out (need to drive a large no of outputs, i.e; more current required) CMOS circuits fail. That is why we use BiCMOS. They are very similar to CMOS circuits except for the BJT(Bipolar Junction Transistor) output stage. BJTs are capable of carrying large currents, hence BiCMOS circuits are used in cases of large current requirements.
Can you apply Norton's theorem in circuits containing diodes and BJTs?
Yes, of course but you must first expand the devices to equivalent circuit models of the appropriate approximation level to get reasonable answers. Such equivalent circuit models will have anywhere from 3 or 4 components to dozens depending on approximation level.
