A diode allows current to flow in one direction while blocking current flow in the opposite direction. It is made up of a p-n junction.
When a voltage is applied across the diode in the forward direction (i.e., positive voltage at the anode and negative voltage at the cathode), the diode conducts current and has a low resistance, allowing the current to flow easily. In the reverse direction, the diode has a high resistance and does not conduct current, blocking the flow of electricity.
The input-output characteristics of a diode describe how the current through the diode vary with changes in the applied voltage. The typical input-output characteristics of a diode are:
Forward bias region: In this region, the diode is forward-biased, and current flows through the diode in the forward direction. The voltage across the diode remains relatively constant, while the current increases rapidly with increasing voltage.
Reverse bias region: In this region, the diode is reverse-biased, and only a small reverse current flows through the diode. The voltage across the diode increases rapidly with increasing reverse voltage.
Breakdown region: In this region, the voltage across the diode increases to a critical value, known as the breakdown voltage. Once this voltage is reached, the diode conducts a large reverse current, and the voltage across the diode remains relatively constant.