How does a Schottky diode conduct electricity?

　How does a Schottky diode conduct electricity?

The advantages of Schottky diode are low impedance, small forward voltage drop, and fast recovery speed, so they are often used in high-frequency high-current rectification and power-down protection circuits. The Schottky diode is also a very good conductor, so how does the Schottky diode conduct electricity?

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

The forward characteristic is like in an electronic circuit, connecting the positive pole of the Schottky diode to the high potential end and the negative pole to the low potential end, the Schottky diode will be turned on. This connection method is called forward bias . It must be explained 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 "threshold voltage", the germanium tube is about 0.2V, and the silicon tube is about 0.6V), the Schottky diode can be directly turned on. After the conduction, the voltage across the Schottky diode remains basically unchanged (the germanium tube is about 0.3V, and the silicon tube is about 0.7V), which is called the "forward voltage drop" of the Schottky diode.

Reverse characteristics In the electronic circuit, the positive pole of the Schottky diode is connected to the low potential end, and the negative pole is connected to the high potential end. At this time, almost no current flows in the Schottky diode, and the Schottky diode is in the cut-off state. This connection is called reverse bias. When the 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 increase sharply, and the Schottky diode will lose its unidirectional conductivity. This state is called the breakdown of the Schottky diode.

The switching of the forward characteristic and the reverse characteristic in the Schottky diode forms the conductivity of the current Schottky diode. Under this kind of conductivity, Schottky diode make better use of their own advantages to maximize the conductivity.