Finding the forward current of diode

In summary, when a Si diode is operated at room temperature (27 °C) with a forward current of 1 mA and a voltage VD of 0.9 V, the forward current is found to be 1 mA. Using the Shockley diode equation and subbing in the values, the forward current can be calculated to be 46.81 mA when the VD is 1 V. However, it is important to double-check calculations to avoid errors.
  • #1
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Homework Statement


A Si diode is operated at the room temperature (27 °C). For a forward current of 1 mA, the voltage VD is found to be 0.9 V. If the VD is 1 V, the forward current = _____ mA. Given that nVT = 26 mV

The answer is 46.81

Homework Equations


Shockley diode equation?

The Attempt at a Solution


I tried to use the shockley diode equation, Id=Is exp(Vd/nVt)
I subbed in values 0.9V and 1mA into eqn to get Is and then using newfound Is to sub into shockley diode eqn again with Vd 1V now. However, I didn't get the answer 46.81mA.

Is there an assumption that I have made wrong? Any help in figuring my mistake out is greatly appreciated. Thank you so much!
 
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  • #2
Please show your working so we can check it.
 
  • #3
NascentOxygen said:
Please show your working so we can check it.
Oh my gosh, as soon as I was typing out my steps and I finally got the answer. Must have keyed in wrong values somewhere in the calculator previously.
So sorry for the trouble but thank you!
 

What is a diode?

A diode is an electronic component that allows current to flow in only one direction. It is made up of a semiconductor material, typically silicon, and has two terminals - the anode and cathode.

What is forward current?

Forward current is the amount of current that flows through a diode when a positive voltage is applied to the anode and negative voltage is applied to the cathode. This is the direction in which a diode allows current to flow.

How do you calculate the forward current of a diode?

The forward current of a diode can be calculated using Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). In this case, the resistance will be the forward resistance of the diode, which is typically around 0.7 volts for a silicon diode. So, the formula for forward current is I = V / 0.7.

Why is it important to find the forward current of a diode?

Knowing the forward current of a diode is important because it helps determine the maximum amount of current the diode can handle without getting damaged. It also helps in designing and troubleshooting electronic circuits that use diodes.

What factors can affect the forward current of a diode?

The forward current of a diode can be affected by temperature, voltage, and the type of material used in the diode. Higher temperatures can increase the forward current, while higher voltages can exceed the diode's maximum current rating. Different materials can also have different forward resistance values, affecting the forward current.

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