Why is Diode reverse saturation current I_s still in the V-I equation when when a diode is forward biased?

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why reverse current or dark saturation current is considered if the diode is forward biased ?
Hi all,

This is not homework help or something, it is my general query. I read that ideal diode equation is given as

1691531494352.png


in above equation Is is the reverse saturation current or dark saturation current (According to this website). And according to most of the study which I did this reverse saturation current doesn't exist while the diode is forward biased, I want to ask that why this parameter is still in equation if it does not exist in first place, thanksUsman
 
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You are misunderstanding. This parameter Is is the multiplier that determines the amount of current that flows when forward biased. It is very important in forward bias. Of course, this equation is for an ideal diode. For a real diode, there are other things that contribute to the reverse biased current. So in a real diode, one typically determines Is by measurements in the forward biased region, not in reverse bias.
 
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Is can also be seen as a "scale current", that is dependent on the area of the diode. That is why it can be used for both modes of operation.
 
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1. Why is Diode reverse saturation current Is still in the V-I equation when when a diode is forward biased?

Diode reverse saturation current Is is a measure of the leakage current that flows in the reverse direction when a diode is biased in the forward direction. This current is still present in the V-I equation because it is an inherent characteristic of diodes and cannot be eliminated. It is important to include this term in the equation to accurately model the behavior of a diode in both forward and reverse bias conditions.

2. What is the significance of Diode reverse saturation current Is in the V-I equation?

Diode reverse saturation current Is is an important parameter in the V-I equation as it affects the overall behavior and characteristics of a diode. It determines the minimum voltage required to turn on the diode and also affects the slope of the forward bias region in the V-I curve. Therefore, it is crucial to include this term in the equation to accurately analyze and design circuits using diodes.

3. Can Diode reverse saturation current Is be ignored in the V-I equation?

No, Diode reverse saturation current Is cannot be ignored in the V-I equation as it is an essential part of the diode's behavior. Neglecting this term can lead to inaccurate results and can affect the performance of the circuit. In some cases, ignoring Is may result in the diode not turning on at all, which can have serious consequences in a circuit.

4. How does Diode reverse saturation current Is affect the V-I curve of a diode?

Diode reverse saturation current Is has a significant impact on the shape and characteristics of the V-I curve of a diode. It determines the minimum voltage required to turn on the diode and also affects the slope of the forward bias region. As Is increases, the diode will turn on at a lower voltage and the slope of the curve will become steeper.

5. Can Diode reverse saturation current Is be controlled or reduced?

Diode reverse saturation current Is is an inherent characteristic of diodes and cannot be controlled or reduced. However, it can be minimized by using diodes with lower reverse saturation current values or by operating the diode at lower temperatures. In some cases, a small amount of Is may be desirable for certain applications, such as in voltage reference circuits.

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