Electronics Handbook/Components/Diodes
Diode
editDiode is a SemiConductor Device made from joining One Positive type Semi Conductor with One Negative Type Semi Conductor .
- - o--[N P]--o +
Diode is an Unijuction device that has two distinct polarities namely Anode which is Negative and Cathode which is Positive . Diode has a circuit symbol
Diode's Characrteristics
editI V Curve
editBreak-over Voltage
edit- Vd = 0.3v for Si and 0.6v for Ge
Operation
edit- V < Vd . I = 0 . Diode does not conduct current
- V = Vd . I = 1 mA . Current starts to flow
- V > Vd . I = ev . Diode conducts current exponentially
Polarities & Biased Voltage
editWhen Diode is connected with a voltage source in such that the polarities of the diode is in opposite with the polarities of the voltage source Diode is said to be Forward Biased and when voltage is greter than Forward biased voltage current will flow and increase exponentially with time in the direction of Pointing Arrow
When Diode is connected with a voltage source in such that the polarities of the diode is in the same with the polarities of the voltage source Diode is said to be Backward Biased Diode does not conduct current