What are the differences between diodes — SUNMATE
What are the differences between diodes
There are many different types of diodes, each with different functions and also different from each other. It is very important to select appropriate products according to their different characteristics.
1. rectifier diode
In principle, the output DC from the input AC is rectified. Taking the magnitude of rectifier current (100mA) as the boundary, the output current greater than 100mA is usually called rectifier.
2. limiting diode
After the diode is turned on in the forward direction, its forward voltage drop remains basically unchanged (0.7V for the silicon tube). Using this characteristic, as a limiting element in the circuit, the signal amplitude can be limited to a certain range. Most diodes can be used as limiting diodes. There are also special limiting diodes for protecting instruments and high-frequency Zener tubes. In order to make these diodes have a particularly strong role in limiting sharp amplitude, diodes made of silicon materials are usually used.
3. switching diode
Under the action of forward voltage, the resistance is very small and in the on state, which is equivalent to an on switch; Under the action of reverse voltage, the resistance is very large and is in the cut-off state, just like an open switch. Using the switching characteristics of diodes, various logic circuits can be formed.
4. zener diode
It is made by using the reverse breakdown characteristics of the diode. The voltage at both ends of the circuit remains basically unchanged and plays a role in stabilizing the voltage. It is a product that replaces the voltage stabilizing electronic diode. The diode, which is made into silicon diffusion type or alloy type, is a diode with a sharp change in the reverse breakdown characteristic curve. It is made as a control voltage and a standard voltage.
5. Schottky diode
Diode of "metal semiconductor junction" with Schottky characteristics. Its forward starting voltage is low. In addition to materials, the metal layer can also be made of gold, molybdenum, nickel, titanium and other materials. Its semiconductor materials are silicon or gallium arsenide, mostly n-type semiconductors. This device is conductive by most carriers, so its reverse saturation current is much larger than that of the PN junction conductive by a few carriers. Because the storage effect of minority carriers in Schottky diode is very small, its frequency response is only limited by RC time constant. Therefore, it is an ideal device for high frequency and fast switching.
6. transient voltage suppression diode
It can provide fast overvoltage protection for the circuit, which is divided into bipolar type and unipolar type.