2. DIODE GUNN
They are used in high frequency
electronics and are characterized
by, under certain conditions,
they present a negative
resistance. Gunn diodes are used
in the construction of
microwave oscillators.
3. UNION DIODES
Are those that consist of a
germanium or silicon crystal,
properly doped, and has a cylindrical
shape. They are low power diodes
that are widely used as rectifiers of
small devices. This kind of diode is
also known as junction diodes.
4. LIGHT-EMITTING DIODES
It is a light source consisting of a
semiconductor material with two
terminals. It is a p-n junction
diode, which emits light when
activated. If an adequate voltage
is applied to the terminals, the
electrons recombine with the gaps
in the region of the p-n junction of
the device, releasing energy in the
form of photons.
5. CAPACITIVE DIODE (VARICAP)
This diode, also called variable
capacity diode, is, in essence, a
semiconductor diode whose main
characteristic is to obtain a capacity
that depends on the inverse voltage
applied to it. It is used especially in
television tuner circuits and FM
radio receivers.
6. ZENER DIODE
Also called voltage regulator diode, we can
define it as a silicon semiconductor element
that has the characteristic of a normal diode
when it works in the direct direction, that is,
in the direction of passage; but in the
opposite direction, and for a reverse current
greater than a certain value, it presents a
voltage of constant value. This phenomenon
of constant voltage in the reverse direction
makes the Zener diodes exceptionally
useful devices to obtain a voltage that is
relatively invisible to variations in the
supply voltage, that is, as voltage regulating
devices.
7. TUNNEL DIODE
Is its negative resistance in a
certain range of direct polarization
voltages. When the resistance is
negative, the current decreases
with increasing voltage.
Consequently, the tunnel diode
can function as an amplifier, as an
oscillator or as a flip-flop.
