Electronics Handbook/Components/Diodes/PN
PN Diode[edit | edit source]
Construction | Symbol | I - V Curve |
---|---|---|
o-- P N --o |
Characteristics[edit | edit source]
I V Curve[edit | edit source]
Conduction[edit | edit source]
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[edit | edit source]
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[edit | edit source]
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