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Ideal diode with a series voltage source and resistor. The I-V characteristic of the final circuit looks like this: I-V characteristic of an ideal diode with a series voltage source and resistor. The real diode now can be replaced with the combined ideal diode, voltage source and resistor and the circuit then is modelled using just linear elements.
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 ...
Using these ideal diodes rather than standard diodes for solar electric panel bypass, reverse-battery protection, or bridge rectifiers reduces the amount of power dissipated in the diodes, improving efficiency and reducing the size of the circuit board and the weight of the heat sink required to deal with the power dissipation.
Zener diodes have a low breakdown voltage. A standard value for breakdown voltage is for instance 5.6 V. This means that the voltage at the cathode cannot be more than about 5.6 V higher than the voltage at the anode (though there is a slight rise with current), because the diode breaks down, and therefore conducts, if the voltage gets any higher.
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 semiconductor diode is not ideal. As shown in the figure, the diode does not conduct appreciably until a nonzero knee voltage (or turn-on, cut-in, or threshold voltage) is reached, whose value depends on the semiconductor (listed in Diode § Forward threshold voltage for various semiconductors). Above this voltage the slope of the current ...
In electrical engineering, modified nodal analysis [1] or MNA is an extension of nodal analysis which not only determines the circuit's node voltages (as in classical nodal analysis), but also some branch currents. Modified nodal analysis was developed as a formalism to mitigate the difficulty of representing voltage-defined components in nodal ...