How do you calculate reverse saturation current?

Reverse saturation current of a P-N junction is modeled by equation: I_s = T(3+1/2) e (-kt)where T is operation temperature in Kelvin’s, k=1.38 times 10^-23 (J/K) Boltzmann constant, E_g is the bandgap energy level of a semiconductor material (eV). gamma is a modeling constant.

From Wikipedia, the free encyclopedia. The saturation current (or scale current), more accurately the reverse saturation current, is that part of the reverse current in a semiconductor diode caused by diffusion of minority carriers from the neutral regions to the depletion region.

One may also ask, what is reverse saturation current Why is it constant? In a PN junction diode, the reverse saturation current is due to the diffusive flow of minority electrons from the p-side to the n-side and the minority holes from the n-side to the p-side. when voltage breakdown occurs,current remains constant and not increase eventhough there is increase of voltage.

Likewise, how do you find saturation current?

2 Answers

  1. Measure current with fairly large reverse bias, to give you Is. ( for example, -20V for a 1N4148)
  2. Measure forward voltage with fairly large forward current (for example, 20mA for a 1N4148) and calculate the emission coefficient: n=VFVT⋅ln(I/IS)

What is meant by saturation current?

Definition of saturation current. : the limiting current through an ionized gas or an electron tube such that further increase of voltage produces no further increase in current.

What is meant by reverse current?

Definition of reverse current. : flow of direct electric current in a reverse direction or of alternating current in phase opposition to normal.

What is reverse breakdown voltage?

The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive. For diodes, the breakdown voltage is the minimum reverse voltage that makes the diode conduct appreciably in reverse.

What is cut in voltage?

Cut-in voltage or knee voltage or threshold voltage is the minimum voltage( in forward bias condition)after which the diode current rises rapidly and diode is said to be conducting for silicon it’s 0.7 volt and for germanium it’s 0.3.

How does reverse saturation current vary with temperature?

Reverse saturation current (IS) of diode increases with increase in the temperature the rise is 7%/ºC for both germanium and silicon and approximately doubles for every 10ºC rise in temperature. Barrier voltage is also dependent on temperature it decreases by 2mV/ºC for germanium and silicon.

What do u mean by diode?

A diode is a specialized electronic component with two electrodes called the anode and the cathode. Most diodes are made with semiconductor materials such as silicon, germanium, or selenium. The fundamental property of a diode is its tendency to conduct electric current in only one direction.

What is knee voltage?

The minimum amount of voltage required for conducting the diode is known as “knee voltage” or “cut-in-voltage”. And also said as The forward voltage at which the current through PN junction starts increasing rapidly is known as knee voltage. Knee voltage of “germanium” diode is-0.3volts.

What is saturation current in photodiode?

Saturation occurs when no additional photocurrent outputs from the photodiode as the incident optical power increases. Since photodiodes output a current, the saturation limit can be adjusted by modifying the reverse bias voltage (within specification) or reducing the load resistance.

What does saturation current depend on?

The saturation current depends on the intensity of the light,for a given frequency. More photons correspond to more electrons. One photon knock out one electron and if you increase the number of photons (or increase the intensity) you increase the current.

How reverse current is produced?

Reverse current is when there is a higher voltage at the output of a system than at the input, causing current to flow backwards through the system. There are two common sources of reverse voltage: (1) when power is disconnected from a system and (2) when the body diode of a FET becomes forward- biased.

How is reverse current obtained?

They are generated due to thermal agitation. Electrons in p side diffuse towards n side and holes from n side diffuse towards p side, due to which a small amount of current flows across the junction, called as leakage current or reverse saturation current.

What is reverse bias current?

reverse bias The applied d.c. voltage that prevents or greatly reduces current flow in a diode, transistor, etc. For example, a negligible current will flow through a diode when its cathode is made more positive than its anode; the diode is then said to be reverse biased. Compare forward bias.

What is forward bias?

Forward bias. Biasing is such an arrangement made in the PN junction device so that the device allows the flow of larger current in one direction. The device is said to be forward biased if the anode is connected to the positive end and cathode is connected to the negative end of the battery.

What is ideality factor?

Ideality Factor. The ideality factor of a diode is a measure of how closely the diode follows the ideal diode equation. In practice, there are second order effects so that the diode does not follow the simple diode equation and the ideality factor provides a way of describing them.