How do Schottky diodes conduct electricity?

How do Schottky diodes conduct electricity?

The advantages of Schottky diodes are low impedance, small forward voltage drop, and fast recovery speed, so they are commonly used in high-frequency high current rectification and voltage drop protection circuits. Schottky diodes are also conductors with excellent conductivity, so how do Schottky diodes conduct electricity?

Unidirectional conductivity is the most important characteristic of Schottky diodes. In a circuit, current can only flow in from the positive pole of a Schottky diode and out from the negative pole. The following is a simple experiment to illustrate the forward and reverse characteristics of Schottky diodes.

The forward characteristic is like connecting the positive terminal of a Schottky diode to the high potential terminal and the negative terminal to the low potential terminal in an electronic circuit, and the Schottky diode will conduct. This connection method is called forward bias. It must be noted that when the forward voltage applied across the Schottky diode is very small, the Schottky diode still cannot conduct, and the forward current flowing through the Schottky diode is very weak.

Only when the forward voltage reaches a certain value (this value is called the "threshold voltage", which is about 0.2V for germanium diodes and about 0.6V for silicon diodes), can Schottky diodes conduct directly and positively. After conduction, the voltage across the two ends of the Schottky diode remains basically unchanged (germanium diode is about 0.3V, silicon diode is about 0.7V), which is called the "forward voltage drop" of the Schottky diode.

In electronic circuits, the reverse characteristic is that the positive terminal of a Schottky diode is connected to the low potential terminal, and the negative terminal is connected to the high potential terminal. At this time, there is almost no current flowing through the Schottky diode, and the Schottky diode is in a cut-off state. This connection method is called reverse bias. When a Schottky diode is reverse biased, there will still be a weak reverse current flowing through the Schottky diode, which is called leakage current. When the reverse voltage across the Schottky diode increases to a certain value, the reverse current will sharply increase, and the Schottky diode will lose its unidirectional conductivity. This state is called Schottky diode breakdown.

The switching of forward and reverse characteristics in Schottky diodes has formed the current conductivity of Schottky diodes. Under this conductivity, Schottky diodes can better utilize their advantages and maximize their conductivity.