Search results
Results from the WOW.Com Content Network
Later he gives a corresponding equation for current as a function of voltage under additional assumptions, which is the equation we call the Shockley ideal diode equation. [3] He calls it "a theoretical rectification formula giving the maximum rectification", with a footnote referencing a paper by Carl Wagner , Physikalische Zeitschrift 32 , pp ...
The Shockley diode equation relates the diode current of a p-n junction diode to the diode voltage .This relationship is the diode I-V characteristic: = (), where is the saturation current or scale current of the diode (the magnitude of the current that flows for negative in excess of a few , typically 10 −12 A).
The Shockley ideal diode equation or the diode law (named after the bipolar junction transistor co-inventor William Bradford Shockley) models the exponential current–voltage (I–V) relationship of diodes in moderate forward or reverse bias. The article Shockley diode equation provides details.
The transfer function of an ideal diode has been given at the top of this (non-linear) section. However, this formula is rarely used in network analysis, a piecewise approximation being used instead. It can be seen that the diode current rapidly diminishes to -I o as the voltage falls. This current, for most purposes, is so small it can be ignored.
The electrons and holes travel in opposite directions, but they also have opposite charges, so the overall current is in the same direction on both sides of the diode, as required. The Shockley diode equation models the forward-bias operational characteristics of a p–n junction outside the avalanche (reverse-biased conducting) region.
As seen in the figure, the current does not increase linearly with applied voltage for a diode. One can determine a value of current (I) for a given value of applied voltage (V) from the curve, but not from Ohm's law, since the value of "resistance" is not constant as a function of applied voltage. Further, the current only increases ...
The characteristic curve (curved line), representing the current I through the diode for any given voltage across the diode V D, is an exponential curve. The load line (diagonal line), representing the relationship between current and voltage due to Kirchhoff's voltage law applied to the resistor and voltage source, is
By the Shockley diode equation, the current diverted through the diode is: = { []} [7] where I 0, reverse saturation current; n, diode ideality factor (1 for an ideal diode) q, elementary charge; k, Boltzmann constant