diode

1. Presentation on-Diode-Diode
ByBy
Suneel kumarSuneel kumar

2. content
• Diode
• Rectifier
• 1-Half wave rectifier
• 2-Full wave rectifier
• Filter
• 1-Active filter
• 2-Passive filter

3. diodediode
A diode is a two-terminal electronic component that
conducts current primarily in one direction it has low
(ideally zero) resistance in one direction, and high
(ideally infinite) resistance in the other. A vacuum
tube diode utilizes thermionic emission of electrons
and unidirectional conduction between the cathode
and plate. A semiconductor diode,

4. N-Type MaterialN-Type Material
N-Type Material:N-Type Material: When extra valence electrons are introducedWhen extra valence electrons are introduced
into a material such as silicon an n-typeinto a material such as silicon an n-type
material is produced. The extra valencematerial is produced. The extra valence
electrons are introduced by puttingelectrons are introduced by putting
impurities or dopants into the silicon. Theimpurities or dopants into the silicon. The
dopants used to create an n-type materialdopants used to create an n-type material
are Group V elements. The most commonlyare Group V elements. The most commonly
used dopants from Group V are arsenic,used dopants from Group V are arsenic,
antimony and phosphorus.antimony and phosphorus.
The 2D diagram to the left shows the extraThe 2D diagram to the left shows the extra
electron that will be present when a Group Velectron that will be present when a Group V
dopant is introduced to a material such asdopant is introduced to a material such as
silicon. This extra electron is very mobile.silicon. This extra electron is very mobile.
+4+4+4+4
+5+5
+4+4
+4+4+4+4+4+4
+4+4+4+4

5. P-Type MaterialP-Type Material
P-Type Material:P-Type Material: P-type material is produced when the dopantP-type material is produced when the dopant
that is introduced is from Group III. Groupthat is introduced is from Group III. Group
III elements have only 3 valence electronsIII elements have only 3 valence electrons
and therefore there is an electron missing.and therefore there is an electron missing.
This creates a hole (h+), or a positive chargeThis creates a hole (h+), or a positive charge
that can move around in the material.that can move around in the material.
Commonly used Group III dopants areCommonly used Group III dopants are
aluminum, boron, and gallium.aluminum, boron, and gallium.
The 2D diagram to the left shows the holeThe 2D diagram to the left shows the hole
that will be present when a Group III dopantthat will be present when a Group III dopant
is introduced to a material such as silicon.is introduced to a material such as silicon.
This hole is quite mobile in the same way theThis hole is quite mobile in the same way the
extra electron is mobile in a n-type material.extra electron is mobile in a n-type material.
+4+4+4+4
+3+3
+4+4
+4+4+4+4+4+4
+4+4+4+4

6. The PN JunctionThe PN Junction
PP nn
- - - - - -- - - - - -
- - - - - -- - - - - -
- - - - - -- - - - - -
- - - - - -- - - - - -
- - - - - -- - - - - -
+ + + + ++ + + + +
++
+ + + + ++ + + + +
++
+ + + + ++ + + + +
++
+ + + + ++ + + + +
++
+ + + + ++ + + + +
++
NaNa NdNd
MetallurgicalMetallurgical
JunctionJunction
Space ChargeSpace Charge
RegionRegionionizedionized
acceptorsacceptors
ionizedionized
donorsdonors
E-FieldE-Field
++++
__ __
h+ drifth+ drift h+ diffusionh+ diffusion e- diffusione- diffusion e- drifte- drift== ==

7. When the voltage is applied to the P-N junction diode in
such a way that the positive terminal of the battery is
connected to the p-type semiconductor and the
negative terminal of the battery is connected to the n-
type semiconductor, the diode is said to be forward
biased.
Forward biasForward bias

8. When this reverse bias voltage is applied to the P-N
junction diode, a large number of free electrons (majority
carriers) in the n-type semiconductor experience an
attractive force from the positive terminal of the battery
similarly a large number of holes (majority carriers) in the
p-type semiconductor experience an attractive force from
the negative terminal of the battery.
Reverse biasReverse bias

9. rectifier
A rectifier is an electrical device that converts
alternating current (AC), which periodically reverses
direction, to direct current (DC), which flows in only
one direction. The process is known as rectification,
since it "straightens" the direction of current

10. Types of rectifiers
Half wave rectifier
As the name suggests, the half wave rectifier is a type
of rectifier which converts half of the AC input signal
(positive half cycle) into pulsating DC output signal and
the remaining half signal (negative half cycle) is
blocked or lost. In half wave rectifier circuit, we use
only a single diode.

11. Full wave rectifier
The full wave rectifier is a type of rectifier which converts
the full AC input signal (positive half cycle and negative
half cycle) to pulsating DC output signal. Unlike the half
wave rectifier, the input signal is not wasted in full wave
rectifier. The efficiency of full wave rectifier is high as
compared to the half wave rectifier.

12. FilterFilter
A filter is an AC circuit that separates some
frequencies from others within mixed-frequency
signals.Audio equalizers and crossover networks are
two well-known applications of filter circuits. a Bode
plot is a graph plotting waveform amplitude or phase
on one axis and frequency on the other
filters are circuits which perform signal processing
functions, specifically to remove unwanted
frequency components from the signal, to enhance
wanted ones, or both. Electronic filters can be

13. Passive filters
Passive implementations of linear filters are based on
combinations of resistors (R), inductors (L) and
capacitors (C). These types are collectively known
as passive filters, because they do not depend upon an
external power supply and/or they do not contain active
components such as transistors

14. Active filters
Active filters are implemented using a combination of
passive and active (amplifying) components, and
require an outside power source. Operational
amplifiers are frequently used in active filter designs.
These can have high Q factor, and can
achieve resonance without the use of inductors.
However, their upper frequency limit is limited by the
bandwidth of the amplifier

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