Transcript Schottky Diode Working and Applications

Schottky Diode Working
and Applications
Schottky Diode Working and
Applications
Introduction:
 Schottky diode is one type of electronic component, which is also
known as a barrier diode. It is widely used in different applications like a
mixer, in radio frequency applications, and as a rectifier in power
applications. It’s a low voltage diode. In This presentation, we discusses
about what is a Schottky diode, construction, applications,
characteristics and advantages.
http://www.elprocus.com/
Schottky Diode Working and
Applications
What is a Schottky Diode?
 Thus creating a Schottky barrier.
 The N-type semiconductor acts as a cathode and the metal side acts as
the anode of the diode.
http://www.elprocus.com/
Schottky Diode Working and
Applications
What is a Schottky Diode?

A Schottky diode is also known as a hot carrier diode.

It’s a low voltage diode.

Schottky diode the voltage drop normally ranges between 0.15 and
0.45volts.

This lower voltage drop provides higher switching speed and better
system efficiency.

In Schottky diode, a semiconductor–metal junction is formed
between a semiconductor and a metal.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Schottky Diode Construction
 It is a unilateral junction.
 A metal semiconductor junction is formed at one end and another metal
semiconductor contact is formed at the other end.
 It is an ideal Ohmic bidirectional contact with no potential existing
between the metal and the semiconductor.
 Schottky diode is a function of temperature dropping.
 It decreases and increasing temperature doping concentration in N type
semiconductor.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Schottky Diode Construction
 Metals of the Schottky barrier diode like molybdenum, platinum, chromium,
tungsten Aluminium, gold, etc., are used and the semiconductor used is N
type.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Schottky Barrier Diode
 A Schottky barrier diode is also known as Schottky or hot carrier diode.
 A Schottky barrier diode is a metal semiconductor.
 A junction is formed by bringing metal contact with a moderately
doped N type semiconductor material.
 The Schottky barrier diode is a unidirectional device conducting current
flows only in one direction.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Schottky Barrier Diode
http://www.elprocus.com/
Schottky Diode Working and
Applications
V-I Characteristics Of Schottky Barrier Diode
 The V-I characteristics of a Schottky barrier diode are below
http://www.elprocus.com/
Schottky Diode Working and
Applications
V-I Characteristics Of Schottky Barrier Diode
 The forward voltage drop of the Schottky barrier diode is very low compared
to a normal PN junction diode.
 The forward voltage drop ranges from 0.3 volts to 0.5 volts.
 The forward voltage drop of Schottky barrier is made up of silicon.
 The forward voltage drop increases at the same time increasing the doping
concentration of N type semiconductor.
 The V-I characteristics of a Schottky barrier diode are very steeper
compared to the V-I characteristics of normal PN junction diode due to the
high concentration of current carriers.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Current Components in Schottky Diode
 The Schottky barrier diode current condition is through majority carriers.
 Which are electrons in an N type semiconductor.
 The formula in the Schottky barrier diode is
 IT= IDiffusion+ ITunneling+ IThermionic emission
http://www.elprocus.com/
Schottky Diode Working and
Applications
Current Components in Schottky Diode
 IDiffusion is diffusion current due to concentration gradient and diffusion
current density.
 Jn=Dn*q*dn/dx for electrons.
 Where Dn is the diffusion constant of electrons.
 q is electronic charge = 1.6*1019coulombs
 dn/dx is a concentration gradient for electrons.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Current Components in Schottky Diode
 ITunneling is the tunneling current due to quantum mechanical tunneling
through the barrier.
 The probability of tunneling increases with the decrease in the barrier or
built in potential and decrease in depletion layer width.
 This current is directly proportional to the probability of tunneling.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Current Components in Schottky Diode
 IThermionic Emission is a current due to thermionic emission current.
 Due to thermal agitation, some carriers have equal energy to or larger
than the conduction band energy to the metal-semiconductor interface,
and to the current flow.
 This is known as thermionic emission current.
 Since the current flowing direction through the Schottky barrier diode is
through majority charge carriers.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Current Components in Schottky Diode
 It is suitable for high-speed switching applications
 because the forward voltage is very low and the reverse recovery time is
very short.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Applications Of Schottky Diode
 Schottky diodes are used for the voltage clamping applications.
 Used to prevention of transistor saturation due to the high current
density in the Schottky diode.
 It’s also be a low forward voltage drop in Schottky diode.
 It t is wasted in less heat, making them an efficient choice for
applications that are sensitive and very efficiency.
 Schottky diodes are also used as rectifiers in power supplies.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Advantages Of Schottky Diode
 Schottky diodes are used in many applications compare to other types
of diodes that do not perform well.
 Low turn on voltage: The turn on voltage for the diode is between 0.2
and 0.3 volts. For a silicon diode it is against 0.6 to 0.7 volts from a
standard silicon diode.
 Fast recovery time: A fast recovery time means a small amount of
stored charge that can be used for high speed switching applications.
 Low junction capacitance: It occupies a very small area, after the
result obtained from wire point contact of the silicon. Since the
capacitance levels are very small.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Features Of Schottky Diode
 The features of Schottky diode mainly include the following
 Higher efficiency.
 Low forward voltage drop.
 Low capacitance.
 Low profile surface-mount package, ultra-small.
 Integrated guard ring for stress protection.
http://www.elprocus.com/
Schottky Diode Working and
Applications
Conclusion
 This is all about Schottky Diode Working and its working principle
and applications. We have seen its construction, Schottky barrier
diode , V-I Characteristics Of Schottky barrier diode.
http://www.elprocus.com/
http://www.elprocus.com/