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Question
What do you mean by zener breakdown and avalanche breakdown?
 Question Submitted By :: Meghana
I also faced this Question!!     Rank Answer Posted By  
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 1
When a high reverse voltage is applied to the highly doped
p-n junction then at a particular voltage breakdown is
occured because of increase in the value of barrier
potential and it increases at such a level that at a
particular voltage the electrons in the atom get ionised
and thus results in the increase in the no of electrons
which results in the rapid increase in the value of current
and this increase in current known as zener breakdown
voltage and the avalanche breakdown occurs when a high
reverse voltage is applied to the normal p-n junction then
due to high voltage the electrons get ejected from the
stationary atoms which results in rapid increase in the
value of current and is known as avalanche breakdown.
 
Is This Answer Correct ?    151 Yes 240 No
Puneesh Makhija
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 2
puneesh makhija is wrong.
Zener breakdown is due to the high electric field present
at the junction.Because of the high E , a sufficiently
strong force exerted on a bound electron by the field to
tear it out of its covalent bond . The new holeelectron pair
created increases the reverse current.(for highly doped
diodes)


Avalanche breakdown is due to collisions . A thermally
generated carrier falls down the junction barrier and
acquires energy from the applied potential . This carrier
collides with a crystal ion and imparts sufficient energy
to disrupt a covalent bond . In addition to original carrier
a new electron-hole pair is generated . This cumulative
process is referred to as avalanche multiplication .
 
Is This Answer Correct ?    427 Yes 53 No
Guest
 
 
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 3
zener breakdown occurs due tos strong electric field across
the diode.when a lower voltage is given ,higher electric
field is generated .due to strong electric field ,the
covalent bonds breakdown and free electrons are generated
when they are sufficient there is sharp rise in current and
breakdown occurs.


avalanche breakdown occurs due to higher velocity of
minority carriers.due to less doping the width of depeletion
region is more.so when a high voltage is given,velocity of
minority carriers increases towards opposite type
semiconductor.when they collide with the walls of
semiconductor,free electrons are generated.when free
electrons are sufficient ,then there is sharp rise in
currents and breakdown occurs.
 
Is This Answer Correct ?    56 Yes 56 No
Debi Prasan Das
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 4
When doping is heavy then in reverse bias even before the
minority charge carriers aquire sufficient velocity the
breakdown occurs. This kind of breakdown is called Zener
breakdown.


When the reverse voltage is increased the width of the
depletion layer increases at the same time due to the force
of attraction and aquire high velocity. During their motion
inside the diodethey collide with the electrons which are
in covalent bonds of the crystaland bring them out of the
bond. Now these two charges again gain sufficient velocity
an da gain collide with the electrons in the covalent bonds
and bring them out. Due to this multiplication process a
large current flows and this kind of breakdown is called
Avalanche multiplication or Avalanche breakdown.
 
Is This Answer Correct ?    38 Yes 34 No
Geethu
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 5
In silicon diodes up to about 5.6 volts, the Zener effect is
the predominant effect and shows a marked negative
temperature coefficient. Above 5.6 volts, the avalanche
effect becomes predominant and exhibits a positive
temperature coefficient.

In a 5.6 V diode, the two effects occur together and their
temperature coefficients neatly cancel each other out, thus
the 5.6 V diode is the component of choice in
temperature-critical applications
 
Is This Answer Correct ?    24 Yes 30 No
Jackkkk
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 6
whenever a pn junction diode is operated in high reverse
bias then the barrier potential increases as a result of
which a high current starts flowing through it.The
breakdown voltage that corresponds to this current shoot up
is called zener breakdowm.
If the reverse bias is high covalont bonds near pn junction
break and large no. of electron and hole pairs are
generated and current shoots.This reverse voltage at which
current shoots is called Avlanche breakdown
 
Is This Answer Correct ?    19 Yes 46 No
Miss. Noopur D. Nayak Shinkre
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 7
In Zener Breakdown , the breakdown is initiated by the the
rupture of the bonds because of the existence of a strong
electric field .
 
Is This Answer Correct ?    21 Yes 20 No
Chinky
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 8
avalanche breakdown occurs in low doped junction.
Breakdownvoltage is greater than 5v. Since it is lightly
doped so, width of depletion layer more therefore
 
Is This Answer Correct ?    11 Yes 21 No
Rahul
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 9
zener breakdown occurs under the influence of strong
electric field.By the strong E.F,more breakage of covalent
bonds take place.Due to which more e-hole pairs come to
play. Then the reverse current rises abruptly and
breaakdown takes place known as zener breakdown.

Under the low influence of electric field in the
junction,the covalent bonds break and more charge carriers
are formed.and under the more reverse voltage,the reverse
current flows and the breakdown due to ore voltage is known
as avlanche breakdown.

call me : 9888976170
 
Is This Answer Correct ?    12 Yes 24 No
Navdeep
 
  Re: What do you mean by zener breakdown and avalanche breakdown?
Answer
# 10
Apropert dop cristal Diode which has a sharp breackdown voltage is known as Zener Diode 
Is This Answer Correct ?    7 Yes 25 No
Shameem Ahmed
 

 
 
 
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