Jul 16, 2015
Institute of CS & IT
Presented Honorably
to Sir Raja Tahir
•What is Diode?
•Different types of diode.
•Rectification.
Presentation outlines
What is Diode?A Diode is the simplest two-terminal unilateral semiconductor device. It allows current to flow only in one direction and blocks the current that flows in the opposite direction. The two terminals of the diode are called as anode and cathode. The symbol of diode is as shown in the figure.
The Ideal Diode Model
Anode Cathode
•Small signal Diode (Small current Diode).
• Large signal Diodes .
•Zener Diodes.
• Light Emitting Diodes (LED) .
• LASER Diode .
•PN Junction diode.
Types of Diode
Small signal Diode
These diodes assumes that the
operating point is not affected
because the signal is small.
Large Signal Diodes
The operating point in these
diodes get affected as the signal
is large.
Zener Diodes
This diode runs in reverse bias
condition when the voltage reaches the
breakdown point. A stable voltage can
be achieved by placing a resistor across
it to limit the current. This diode is used
to provide reference voltage in power
supply circuits
Light Emitting Diodes (LED)
This is the most popular kind of
diode. When it works in the
forward bias condition, the current
flows through the junction to
produce the light.
LASER Diode
This diode produces laser type
of light and are expensive as
compared to LED. They are
widely used in CD and DVD
drives.
PN Junction Diode
These diodes are used to allow current to
flow in one direction while blocking
current flow in the opposite direction.PN
junction diode is a typical diode
Rectification
The process of converting A.C
waveform into d.c waveform is called
Rectification.
Methods:
• Half-wave Rectification
• Full-wave Rectification
Half-wave Rectification
A type of rectification in which one half
cycle of the input A.C current is
converted into d.c current
Half-wave Rectification
Full-wave Rectification
A type of rectification in which both the
input cycles of A.C current is converted
into d.c current.
Full-wave Rectification
A.C Input
d.c output
Rectifier with four diodes
• One input halfcycle
Full-wave Rectification
A.C Input
d.C output
Full-wave Rectification
• Second input halfcycle
A.C Input
d.c output
Thank You