Operating principle and application knowledge of switching diodes

Mobile phones, TVs and refrigerators are all very common items in daily life, and they are also indispensable things in people's daily life. The use of smart appliances brings convenience to life, and switching diodes are indispensable. Switching diodes and MOS tubes can be found on household appliances such as home washing machines, smart refrigerators, and air conditioners. The previous editor talked about capacitors for two months. Today, I will introduce the principle of switching diodes.

Switching diodes are a class of diodes specially designed and manufactured to be "on" and "off" on a circuit. Compared with ordinary diodes, the time from on to off or from off to on is shorter. The conduction of the semiconductor diode is equivalent to a closed switch, and when it is turned off, it is equivalent to opening (opening), so the diode can be used as a switch, and the commonly used type 1N4148 switch diode. PN junction conduction Due to the unidirectional conduction property of semiconductor diodes, the PN junction is turned on under forward bias, and the resistance in the on state is very small, about tens to hundreds of ohms; under reverse bias , The resistance of the PN junction is very large. Generally, the silicon diode is above 10 ohms, and the germanium tube also has tens of thousands of ohms to hundreds of thousands of ohms. Through this characteristic, the diode can control the current in the circuit, making it an ideal electronic switch.

The above description is actually applicable to any ordinary diode, or its own principle. But for switching diodes, the characteristic is the performance at high frequency. At high frequency, the barrier capacitor of the diode has extremely low impedance and parallel diodes. If the capacitance of the barrier capacitor itself reaches a certain level, it will seriously affect the switching performance of the diode. In extreme cases, the diode will be short-circuited, and the high-frequency current will no longer pass through the diode, but bypass the barrier capacitance directly, causing the diode to fail. Moreover, the barrier capacitance of the switching diode is generally very small, which is equivalent to blocking the path of the potential barrier capacitance and achieving a good unidirectional conduction effect at high frequencies.

The above is about the principle and application knowledge distribution of switching diodes, knowledge sharing on the application of household appliances water dispensers, more application and selection knowledge of diodes, triodes, capacitive optocouplers, and can be bookmarked. Click on the consulting service for detailed inquiry, for you Bring more electronic components industry information.