LED and PIN diodes are the common two basic components in the electronics world. Hope this slide will help you to get some idea regarding them.

1. W E L C O M E !
MUHSIN BAKHTIAR MAFAZ (1409054)
FARHAN MAHMUD HEMEL (1409051)
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2. L E D & P i n D i o d e
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3. LED

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A light emitting diode (LED) is
essentially a PN junction opto-
semiconductor that emits a
monochromatic (single color) light when
operated in a forward biased direction.
W h a t i s
L E D ? ?

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H o w d o e s
L E D
w o r k s ? ?
Sufficient voltage is applied to the chip across the
leads.
Electrons moves easily in one direction across
the junction between the p and n regions.
P region contains many more positive than
negative charges.
Voltage is applied and the current starts to flow.
Electrons in the n region contains sufficient
energy to move across the junction into the p
region.
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H o w d o e s
L E D
w o r k s ? ?
Electron recombines with a positive charge.
Electric potential energy is converted into
electromagnetic energy.
For each recombination of a negative and a
positive charge, a quantum of electromagnetic
energy is emitted in the form of a photon.
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7. K I N D S O F L E D
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Starburst
7-
Segment Dot Matrix
Baragraph

8. A p p l i c a t i o n o f L E D
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Sign Applications
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LED Signals
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Illuminations
Sensor Applications
Mobile Applications
Automative Uses

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Benefits
Long
Lifetime
Design
Flexibility
Directional
Energy
Efficiency
Power
supply
Eco
Friendly
LED’s can be controlled for brightness and color.
With LED’s you can direct the light
where you want it, thus no light is
wasted.
A low-voltage power supply is
sufficient for LED illumination.
LEDs have a lifespan of up to 60,000
hours compared to 1,500 hours for
incandescent bulbs. An LED light will
last over 7 years.
LEDs are extremely energy efficient
and consume up to 90% less power
than incandescent bulbs
LED lights contain no toxic materials and
are 100% recyclable.
ADVANTAGES

10. PIN Diode

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A PIN diode is a diode with a wide,
lightly doped 'near' intrinsic
semiconductor, region between a p-type
semiconductor and an n-type
semiconductor region.
The p-type and n-type regions are
typically heavily doped because they
are used for ohmic contacts.
D E F I N I T I O N

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Point 1
The speed of the PIN diode is limited by variation
in the time it takes electrons to pass through the
device. This time spread can be spread in two
ways:
 By increasing the bias-voltage
 By reducing the thickness of intrinsic
layer
Point 2
The PIN diode an inferior rectifier but it
makes the PIN diode suitable for
attenuators, fast switches,
photodetectors, and high voltage
power electronics applications.
Point 3
 TYPES:
 Metal-Semiconductor PIN diode
 Heterojunction PIN diode
I N T R O D U C T I O N
The wide intrinsic region is in
contrast to an ordinary PN diode.
In it :

13. CONSTRUCTION

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When the forward bias control current of the
PIN diode is varied continuously, it can be used
for attenuating, leveling, and amplitude
modulating an RF signal.
OPERATIONS
The basic operation of a pin diode
includes:
When the control current is switched on and off,
or in discrete steps, the device can be used for
switching, pulse modulating, and phase shifting
an RF signal.
When the diode is forward biased, holes and
electrons are injected into the I-region. This
charge does not recombine instantaneously,
but has a finite lifetime (t) in the I-region.
If the PIN diode is reverse biased , there is no
stored charge in the I-region and the device
behaves like a Capacitance (CT) shunted by
a parallel resistance (RP).

15. C O N C E P T
A drawing of a PIN diode chip is shown in Figure 1.1
(a). The performance characteristics of the PIN diode
depend mainly on the chip geometry and the
processed semiconductor material in the intrinsic or I
- region, of the finished diode.
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16. A P P L I C A T I O N S
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It is used as a Photo Detector for most fiber
optic application. The greater depletion improves
the conversion of light to current.
Photo Detector
As the intrinsic region provides a greater
separation between the P & N regions, allowing
higher reverse voltage to be tolerated.
High Voltage Rectifier
They are used in electronic pre-amplifier to
boost sensitivity.
Electronic Pre-amplifier
Widely used in RF modulator circuit to control RF
intermodulation distortion. At high frequencies, the pin
diode acts as a resistor.(in attenuetor designs).
RF Modulation
This diode In a phase shifter circuit is
considered as a lumped variable-impedance
microwave circuit element.
In Phase Shifting Ckt
The PIN diode makes an ideal RF Switch. The intrinsic
layer between the P & N regions increases the distance
between them, thereby increasing the level of isolation in
reverse bias condition.
RF Switch

17. ABOUT US!
Dept. of Electronics & Communication Engineering
Khulna University of Engineering & Technology
01953889101
01940278741

18. THANK YOU!