Table of Contents
- 1 What are the factors governing the reverse saturation current in a pn junction diode?
- 2 What is reverse saturation current why it depends on temperature?
- 3 How does the reverse saturation current of a pn diode vary with temperature?
- 4 Why does the reverse current increase on increasing temperature?
- 5 How is reverse saturation current generated?
- 6 How do you control reverse current?
- 7 What is reverse saturation current in a PN junction diode?
- 8 What is the saturation current?
What are the factors governing the reverse saturation current in a pn junction diode?
The factors governing the reverse saturation current in a PN junction diode are:
- Voltage, if you exceed the breakdown the diode dies.
- Temperature, current roughly doubles for every 10ºC temperature increase.
- Area of the junction, larger area, larger current.
What is reverse saturation current why it depends on 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 are the factors which affect the leakage current when the diode is reverse biased?
When a diode is reverse biased, the width of the depletion region increases. Generally, this condition is required to restrict the current carrier accumulation near the junction. Majority current carriers are primarily negated in the depletion region and hence the depletion region acts as an insulator.
Does saturation current depend on temperature?
Although the saturation current is voltage independent, it does depend on temperature since both the current contributions depend on thermally stimulated carriers.
How does the reverse saturation current of a pn diode vary with temperature?
Reverse saturation current: The reverse saturation current of the diode increases with an increase in the temperature. The rise is 7\% /°C for both germanium and silicon and approximately doubles for every 10°C rise in temperature.
Why does the reverse current increase on increasing temperature?
This is because when the temperature is increased, more electron-hole pairs are generated and due to this the conductivity will increase, and thus current will also increase. When the temperature increases by 10∘ for both germanium and silicon the reverse current will approximately get double.
What is the cause of reverse breakdown?
Zener breakdown occurs because of the increase in the electric field. High electric field increases break the covalent bonds which result in the increase of charge carriers. In Avalanche breakdown, the velocity of the minority carriers is increased by the increase in the electric field.
Does reverse saturation current of the diode change significantly in magnitude for the reverse bias potentials?
The change of the reverse saturation current is significant but it is fairly steady for changes in the reverse-bias potentials so the resulting change is small.
How is reverse saturation current generated?
In a well made diode, the reverse saturation current is caused by thermally generated electron-hole pairs. 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.
How do you control reverse current?
There are three common ways to protect from reverse current: diodes, FETs, and load switches. Diodes are great for high-voltage, low-current applications. However, diodes cause a forward-voltage drop which increases total power dissipation in the system and limits VCC by 0.6 V to 0.8 V.
Does reverse diode depend on voltage?
The current flows effortlessly while in forward bias, but reverse bias does not permit current to flow through the diode. The level of the current depends on the forward voltage while in forward bias, however, the amount of current is minimal or negligible in reverse bias.
What is the effect of temperature on reverse saturation current?
The reverse saturation current is almost independent of the applied reverse bias voltage, but increases with the rise of temperature of the junction diode. This is because the minority carrier density contributing proportion increases with the rise of temperature.
What is reverse saturation current in a PN junction diode?
In a PN junction diode, the reverse saturation currentis 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. Hence, the reverse saturation current depends on the diffusion coefficient of electrons and holes
What is the saturation current?
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.
What is the effect of temperature on reverse breakdown voltage?
Reverse breakdown voltage (VR) also increases as we increase the temperature. PN junction diode parameters like reverse saturation current, bias current, reverse breakdown voltage and barrier voltage are dependent on temperature. Rise in temperature generates more electron-hole pair thus conductivity increases and thus increase in current