Electronics Handbook/Components/Diodes/PN

PN Diode Construction Symbol I - V Curve o-- P N --o Image:Diode symbol.svg 200px Characteristics I V Curve 300 Conduction When connect Voltage source's Polarities the same with Diode's Polarities . Diode does not conduct . No current can flow When connect Voltage source's Polarities different with Diode's Polarities . Diode conducts . current can flow Biasing Voltage Diode does not conduct current with voltage below Conducting Voltage . Conducting voltage is the voltage at current equals to 1mA . For Si the conducting voltage is 0.3 v . For Ge the conducting voltage is 0.6 v . Diode's Conducting Voltage is denoted as Vd V > Vd . Diode conducts current , I ≠ 0 V < Vd . Diode does not conduct current , I = 0 With this characteristic Diode can be used like a mechanical switch . Switch opens equivalent to V < Vd . Switch closes equivalent to V > Vd Current With voltage greater than Diode's Conductng Voltage . The change in current with change in voltage can be expressed as an exponential of Euler's constant e When the value of V >> Vd ≈ 100v the I = Io