Under reverse polarization, the externally used voltage V pulls the holes in the p side as well as the electrons in the n side far from the junction. The width of the exhaustion Layer as well as the elevation of the barrier rise as necessary.
The boost in the obstacle energy is gauged in eV. This rise of the barrier elevation decreases the current to a minimal worth, because very couple of bulk carriers can currently go across the junction by surmounting the boosted barrier.
On the other side, the variety of minority carriers moving down the potential obstacle is left untouched given that this number depends (mainly) on the temperature level. As a result of this device, a small current called the “reverse saturation current” flows. The reverse saturation current is virtually independent of the used opposite predisposition voltage, however increases with the surge of temperature level of the junction diode. This is due to the fact that the minority carrier thickness adding proportion boosts with the surge of temperature level.
Difference between reverse saturation and leakage current
In an ideal diode, they are the same. The diode equation is:
so if you apply a strong reverse bias (v≪0), then the reverse current will be very close to Is, the saturation current.
In a real diode, there may be other leakage courses in addition to with the PN junction itself that enable current to pass, so the leakage current may be greater than the saturation current. For a diode placed on a PCB, there could be extra leakage as a result of surface contamination.
On a IV Characteristic curve of a PN junction diode, you will usually have a really reduced reverse bias current (Leakage current). This current is claimed to be 1uA in the most extreme problems for a silicon small signal diodes.
The ‘Reverse Saturation Current’ is likewise called the Zener diode Breakdown voltage or the ‘Avalanche Region’. This current will drastically raise as the Reverse Break down Voltage is accomplished and probably ruined your diode unless you have a high resistance in collection to restrict the current flowing through the diode in break down problems.
If you are checking out a requirements for a PN junction diode, I would certainly think the reverse saturation current is defined as a maximum. This will certainly offer you assistance on what resistor you must place in collection with the diode to safeguard your circuit.
On a typical diode. When its reverse bias the deficiency area expands. Tis impact triggers the diode to come to be a capacitor (there are unique diodes that are enhanced to work such as this and also used as a variable capacitor). The reverse prejudice leak current is the insulation break down of this diode in its capacitance state. The exhaustion break down voltage is the voltage potential at which the diode will carry out in reverse prejudice. Given that the typical pn junction diode is not constructed like a zener diode (zener diodes really have pn-pn arrangements on its die inside), it will certainly short out in its regular circuit layout due to the absence of current limiting. Zener diodes have to be current restricted (usually by a resistor in series) so it can preserve this reverse bias voltage potential without the current escaping causing the diode to brief.