The function of Schottky diode
The Schottky diode is also called Schottky barrier diode (SBD). It is a kind of semiconductor device with a low power consumption and an extreme high speed. It is applied extensively in circuits, such as the switching power supply, frequency converter and driver, etc. It is used as a large current rectifier diode, follow current diode and protection diode of high frequency and low voltage, or used as a rectifier diode, small signal detection diode in the microwave communications, etc. circuits.
The structure of Schottky diode
The Schottky diode is very different from a diode of PN junction. Its inside is constructed by anode metal (barrier layer using materials, such as molybdenum and aluminium, etc.), silicon dioxide (SiO2) electric field elimination material, N-epitaxy layer (arsenic material), N type silicon substrate, N+ cathode layer and cathode metal, etc. The Schottky barrier is formed between the N type substrate and the anode metal. If a positive bias is applied across both terminals of the Schottky barrier (the anode metal is connected to positive power supply, the N type substrate is connected to negative power supply), the Schottky barrier layer is narrowed down, and its internal resistance is reduced; Inversely, if a negative bias is applied across both terminals of the Schottky barrier, the Schottky barrier layer is enlarged, and its internal resistance is increased.
The Schottky diode is divided into two kinds of packing, i.e. the leading line and the surface installation (chip) types.
The Schottky diode of the leading line type packing is usually used as a large current rectifier diode, follow current diode and protection diode of high frequency. It has two kinds of packing forms, i.e. mono-diode and dual-diode (duodiode).
The Schottky darling pair diode is divided into three types of leading, i.e. common cathode (negatives of two diodes connected with each other), common anode (positives of two diodes connected with each other) and serial connection (the positive of a diode connected to the negative of another diode).
The Schottky diode that adopts the surface packing has multiple packing forms, such as the mono-diode type, dual diode type and three diode type, etc. There are A~19 kinds of pin leading methods.