Volt-Ampere Characteristics Of Diodes

The diode has unidirectional conductivity, and the volt-ampere characteristic curve of the diode is .

A forward voltage is applied to the diode. When the voltage value is small, the current is extremely small; when the voltage exceeds 0.6V, the current begins to increase exponentially, which is usually called the turn-on voltage of the diode; when the voltage reaches about 0.7V, the The diode is in a fully conducting state, and this voltage is usually referred to as the diode's turn-on voltage, denoted by the symbol UD.

For germanium diodes, the turn-on voltage is 0.2V and the turn-on voltage UD is about 0.3V. A reverse voltage is applied to the diode. When the voltage value is small, the current is extremely small, and its current value is the reverse saturation current IS. When the reverse voltage exceeds a certain value, the current begins to increase sharply, which is called reverse breakdown. This voltage is called the reverse breakdown voltage of the diode and is represented by the symbol UBR. The breakdown voltage UBR value of different types of diodes varies greatly, from tens of volts to several thousand volts.