Biasing Diodes Flashcards
refers to the use of DC voltage
to establish the operating condition
of an electronic device.
Bias
is the condition that allows
current to flow through the PN
junction.
Forward Bias or ON condition
The ______ of the dc
source must be connected to
the ___ and the bias
voltage ____ for the
forward bias condition.
positive terminal ,p region ,must be greater than
the barrier potential
Forward Bias Currents
N Region
Majority Carriers are Free Electron
Minority Carriers are Holes
Forward Bias Currents
P Region
Majority Carriers are Holes
Minority Carriers are Free Electrons
Effect on the Depletion Region
As more ________ flow into the depletion region, the
number of ____ is reduced so as more ___ flow to the
depletion region, the number of _____ is reduced. This
result to the _______.
free electrons, positive ions,holes,negative ions,narrowing of the depletion region
Barrier Potential
During forward bias condition the __ in the n region ________ to climb the energy hill and _____.
free electrons,gains enough
energy,cross
the depletion region.
After crossing the depletion region the ________ and combines with the holes in p region. The _____ results in a ________ and is
equal to the ______ depending on the semiconductor used. An additional voltage drop occurs in the p and n regions due to ________ called ____and can be neglected.
free electron gives off energy , energy loss, voltage drop in the PN junction,barrier potential,internal resistance ,dynamic
resistance
is the condition of the diode
that prevents current through
the diode.
Reverse Bias or OFF condition
Reverse Bias
The ____ of the dc
source must be connected to
the ____ or the ________ for the reverse bias
condition.
negative terminal ,p region,bias voltage
is less than the barrier
potential
Reverse Bias Condition
In the n region the ___________ creating additional
positive ions. In the p region the
___________creating additional
negative ions. The additional ions
results in _____.
positive potential
pulls the free electrons away from the
PN junction and, electrons from the voltage source
enters as valence electrons moving
from hole to hole ,widening of the depletion
region.
Reverse Currents
The extremely small reverse
current in a diode called _________ is due to the minority carriers from
electron-hole
pairs.
saturation current (IS), thermally generated
Reverse Currents
A small reverse current that flows on the surface of the crystal which is caused by surface impurities and imperfection on the crystal structure.
Surface Leakage Current
The surface leakage
current is __________ to the
reverse voltage.
directly proportional
It is a condition in the semiconductor PN junction when the reverse bias exceeds a certain value creating an electric field strong enough to dislodge charge carriers from an atom and these carriers flow freely across the PN junction in the opposite direction.
Zener Effect
