what is a diode? What are the features?

what is a diode? What are the features?

The shape and structure of the diode.

Characteristics of the diode

The second plate has a unidirectional conductivity,allowing only the current to flow from the positive to the negative,and the current is not allowed to flow from the negative to the positive.The germanium diode and the silicon diode have different forward tube voltage drops during forward conduction.Figure 5-1 shows that when the forward voltage is greater than the forward voltage drop, the diode is on.The forward voltage of the germanium diode is about 0.3V.The forward voltage of the silicon diode is greater than 0.7V.In addition, at the same temperature,the reverse leakage current of the silicon diode is much smaller than that of the germanium diode. From the above volt-ampere characteristic curve,the voltage and current of the diode are nonlinear,and the diode is a nonlinear semiconductor device.

What are the main parameters of an ordinary diode?

Maximum rectified current IFM maximum rectified current is the maximum average current that is allowed to pass through the PN junction. The actual operating current in use should be less than IFM, otherwise the diode will be damaged.

Maximum reverse voltage URM maximum reverse voltage refers to the maximum reverse voltage applied to both ends of a diode without causing breakdown of PN junction. The use of URM should be greater than the actual operating voltage of more than 2 times the diode.

Reverse current Ico reverse current refers to the current passing through the diode under the specified reverse voltage on the diode. Silicon tube 1A or less, germanium tube is about several hundred microamperes. The smaller the reverse current in use, the better.

Maximum operating frequency ( fm ) The maximum operating frequency is the highest frequency of the diode that guarantees good operating characteristics. At least 2 times the actual operating frequency of the circuit.