NAME ASHLEY MADOMBGWE
REG NUMBER R228623N
PROGRAM HFOSCP
COURSE WORKSHOP PRACTICE AND TECHNOLOGY
CODE HFOSCP202
TITLE DIODES AND TRANSISTORS
1. All types of diodes and their applications.
Type of diodes Applications Advantages Disadvantages
1. Rectifier Convert AC - Low cost -Temperature
diodes ( Alternating current) to - Efficient AC to dependent
DC (direct current) in DC conversion performance
power supply circuits, -Limited surge
battery chargers current capability
2. Zener diodes Voltage stabilization – - Overvoltage -Limited voltage
maintain constant protection range
voltage in power - Low cost -Reverse current
supplies, audio leakage
equipment and medical
devices
3. Light emitting - Residential lighting - energy efficient - colour temperature
diodes i.e. bulbs - long lifespan as they have a cold,
- Display backlighting bluish tone
i.e. smartphones - interference as
they can emit
electromagnetic
interference
4. Schottky - High frequency - Fast switching - Limited voltage
diodes switching times rating
- Power supplies - High current - Noise sensitivity
density
5. Varactor Voltage-controlled - Low series - Sensitive to
diodes capacitors in tuning resistance temperature changes
effect and frequency - Low noise - Limited current
modulation handling
6. Photodiodes - Optical - High sensitivity to - Limited dynamic
communication systems light range
- image sensors - Fast response time - Limited lifespan
2. Two types of transistors (BJT & FET) and applications
A transistor is a semiconductor device that can amplify or switch electric signals. There are
two primary types of transistors namely Bipolar Junction Transistors (BJTs) and Field-Effect
Transistors (BFTs).
I. Bipolar Junction Transistors consists of three layers which are base , collector and
emitter. The base is thin and lightly doped while the collector and emitter are thicker
and more heavily doped. There are two types : NPN and PNP.
BJTs are widely used in amplifiers due to their high gain and linearity. They are used
in switching applications as they can n handle high current and voltages. Mostly used
in analog circuits for their precise control over current
These applications are largely based on these properties which are high current gain,
fast switching and linear response ideal for analog signal processing.
II. Field-Effect Transistors have three terminals namely spruce , drain and gate. There
are two types Junction FETs (JFETs) and Metal-Oxide-Semiconductor FETs
( MOSFETs). Their operation is to control the flow of current with an electric field.
The current between the source and drain is controlled by the voltage applied to the
gate.
FETs specifically MOSFETs are used in digital including microprocessors and
memory devices. They are used in switching applications due to their high efficiency
and low power consumption. They are used in analog circuits for their high
impedance and low noise.
These applications are a result of characteristics such as high input impedance
minimizing loading effect on preceding stages, low power consumption and high
speed switching.
References
1. Pulfrey, D.L. (2010). Understanding Modern Transistors and Diodes. Cambridge
University Press.
2. Korneff, T. (2012). Introduction to Electronics. Elsevier.
3. Reid, K.J. and Dueck, R.K. (2008). Introduction to Digital Electronics. Cengage
Learning.
4. Sierra Circuits. (n.d.). Basic Electronic Components. [online] Available at:
https://www.protoexpress.com/kb/basic-components-overview/.
5. Renesas. (2024). Diodes, Transistors and FETs. [online] Available at:
https://www.renesas.com/en/support/engineer-school/electronic-circuits-02-
diodes-transistors-fets [Accessed 10 Oct. 2024].
