On what condition a tunnel diode can be used as switch?

The tunnel diode is used as a fast switching device in computers as well as in high frequency oscillators and amplifiers. Symbol of Tunnel Diode The symbol for Tunnel Diode is shown in the figure below. An anode is a positively charged electrode that attracts electrons.

What is the principle of operation of tunnel diode?

Tunnel Diode is the P-N junction device that exhibits negative resistance. When the voltage is increased than the current flowing through it decreases. It works on the principle of the Tunneling effect.

What are the characteristics of tunnel diode?

Tunnel diode theory shows that it does not act as a normal diode, but instead exhibits a negative resistance region in the forward direction. The I-V characteristic curve, combined with the very high speed of the diode mean that the it can be used in a variety of microwave RF applications as an active device.

Why is it called a tunnel diode?

The name “tunnel diode” is due to the quantum mechanical tunneling is responsible for the phenomenon that occurs within the diode. The doping is very high so at absolute zero temperature the Fermi levels lies within the bias of the semiconductors.

Can a tunnel diode be used as an amplifier?

The Tunnel diode exhibits negative resistance in their operating range. Therefore, it can be used as an amplifier, oscillators and in any switching circuits. What is a Tunnel Diode? Tunnel Diode is the P-N junction device that exhibits negative resistance. When the voltage is increased than the current flowing through it decreases.

What causes the current to decrease in a tunnel diode?

A Tunnel diode is a heavily doped p-n junction diode in which the electric current decreases as the voltage increases. In tunnel diode, electric current is caused by “Tunneling”. The tunnel diode is used as a very fast switching device in computers. It is also used in high-frequency oscillators and amplifiers.

How does a tunnel diode oscillator generate microwave frequencies?

The figure-3 depicts tunnel diode based oscillator circuit. The circuit helps generate microwave frequencies upto 100 GHz. As shown in the figure-3, tunnel diode is connected in series with the tank circuit. When power is applied surge current produces oscillation in the tank.

How does heavy doping affect a tunnel diode?

Heavy doping results in a narrow depletion region. When compared to a normal p-n junction diode, tunnel diode has a narrow depletion width. Therefore, when small amount of voltage is applied, it produces enough electric current in the tunnel diode.