Electronic Devices and Circuits
Engineering Sciences 154

Load Line Concept and Diode Circuits

Consider the following circuit:
where NLD is a nonlinear device (e.g., a diode) which has a known IV characteristic.  Since VD must satisfy both the known IV characteristic and the equation

both may be plotted on the same graph as in the following diode example:


Forward biased

Reverse biased
 

Another interesting example of a NLD is the (Esaki) tunnel diode which has a region of "negative" resistance in its characteristic.


Characteristic of an Esaki (tunnel) diode

Monostable operation of an Esaki (tunnel) diode

Bistable operation of an Esaki (tunnel) diode

Astable operation of an Esaki (tunnel) diode
 
Tunnel Diode Oscillator
The excess small forward current flow in a tunnel or Esaki diode is a manifestation of quantum mechanical tunneling.  Consider the following pictures:

 
 
 

This page was prepared and is maintained by R. Victor Jones
Comments to: jones@deas.harvard.edu.

Last updated October 19,  2001