The document discusses the invention of the transistor by William Shockley, John Bardeen, and Walter Brattain in 1947, and explains its function as a semiconductor device used to amplify or switch electronic signals. It describes different types of bipolar junction transistors (n-p-n and p-n-p), their operational regions, and applications as switches and amplifiers in electronic circuits. The document also highlights various configurations for connecting transistors and addresses their limitations and future advancements in technology.

2. Group member:

3. Our Topic Based On Transistor

4. Inventor Of Transistor:
The first transistor was invented at
Bell Laboratories on December 16,
1947 by William Shockley (seated at
Brattain's laboratory bench), John
Bardeen (left) and Walter Brattain
(right).

5. Transistor
A transistor is a semiconductor
device used to amplify or switch
electronic signals and electrical
power. It is composed of
semiconductor material with at
least three terminals for connection
to an external circuit.

6. Type Of Transistor:
The most common type of transistor is called bipolar junction
transistor and these are divided into two types.
They Are:
i) n-p-n transistor :
#Base is energized to allow current flow
ii) p-n-p transistor
#Base is connected to a
lower potential to allow current flow

7. n-p-n BJT Transistors
1. High potential at
collector
2. Low potential at
emitter
3. Allows current flow
when the base is given a
high potential

8. p-n-p BJT Transistors
1. High potential at
emitter
2. Low potential at
collector
3. Allows current flow
when base is connected
to a low potential

9. 1. Cut-off Region: VBE < VFB, iB=0
Transistor acts like an off switch
2. Active Linear Region: VBE=VFB, iB≠0, iC=βiB
Transistor acts like a current amplifier
3. Saturation Region: VBE=VFB, iB>iC,max/ β
In this mode the transistor acts like an on switch
4. Power across BJT
BJT Modes

10. Region of Transistor:
A transistor has three regions namely,
1. Emitter
2. Base
3. Collector

11. Emitter:
The section on one side that supplies charge carriers (electron or holes) is
called the emitter. The emitter is always forward biased w.r.t. base so that it
can supply a large number of majority carriers.

12. Collector:
The section on one side that collects charges is called the
collector. The collector is always reverse biased w.r.t. base.
Its function is to remove charges from its junction with
the base.

13. Base:
The middle section which forms two pn junctions between the emitter
and the collector is called the base. The base-emitter junction is forward
biased, allowing low resistance for the emitter circuit. The base-collector
junction is reverse biased and provides high resistance in the collector
circuit

14. A transistor has two pn junctions.
They Are:
1. Forward biased junction
2. Reverse biased junction
P-N Junction Diodes

15. Forward Bias
1.Current flows from P to N
2. The forward biased junction has a low resistance path

16. Reverse Bias
1. No Current flows
2.Excessive heat can cause dopants in a
semiconductor device
to migrate in either direction over time,
degrading diode
3. a reverse biased junction has a high
resistance path

17. Transistor application
Transistors have two functions.
They act as switches or as amplifiers.

18. Transistor as a switch :
When used as an electronic switch, the transistor is normally
operated alternately in cut-off and saturation regions.
Transistor applications

19. Transistor as amplifier :
Due to the small changes in base current the
collector current will imitative the input with
greater amplitude
Transistor applications

20. A transistor can be connected in a circuit in following three configurations:
1. Common base connection (CB)
2. Common emitter connection (CE)
3. Common collector connection (CC)
Transistor Connections

21. Common base connection:
In this connection input is applied between emitter and base
and output is taken from collector and base. Here, base of the
transistor is common to both input and output circuits

22. Current amplification Factor, a(alpha) : It is the ratio of output current to input
current. In a common base connection, the input current is the emitter current
IE and output current is the collector current IC.

23. In this connection input is applied between base and emitter and output
is taken from collector and emitter. Here emitter of the transistor is
common to both input and output circuits and as shown in figure.

24. Base Current amplification Factor ß :
In this configuration, input current is IB and output current IC.
The ratio of change in collector current to the change in base current is
known as base current amplification factor i.e.

25. Common Collector Connection
In this arrangement input is applied between base and collector and output is
taken from emitter and collector. Here collector of the transistor is common
to both input and output circuits and as shown in Figure .

26. In this configuration, input current is IB and output current IE.
The ratio of change in emitter current to the change in base current is known
as base current amplification factor i.e.
Current amplification Factor

27. 1. silicon transistors can age and fail
2. high-power, high-frequency operation, such as that used in over-the-air
television broadcasting, is better achieved in vacuum tubes due to improved
electron mobility in a vacuum;
3. solid-state devices are susceptible to damage from very brief electrical and
thermal events, including electrostatic discharge in handling; vacuum tubes are
electrically much more rugged;
4. sensitivity to radiation and cosmic rays (special radiation-hardened chips are
used for spacecraft devices);
5. vacuum tubes in audio applications create significant lower-harmonic
distortion, the so-called tube sound, which some people prefer.
Limitation:

28. 1. Molecular electronics
2. Carbon nanotube transistors
3. Nano inspiration wire transistors
4. Quantum computing
5. CMOS devices will add functionally to CMOS non-volatile memory,
opt-electronics, sensing and etc. etc.
6. Biology may provide for new technologies bottom-up assembly
,human intelligence .
Future of transistor:

29. Thank You All