Created By : awnish

Reviewed By : Phani Ponnapalli

Last Updated : Apr 10, 2023

Make use of the Shockley Diode Calculator to find the voltage drop or current flow in the real diode quickly by providing thermal voltage, saturation current & others. Just enter emission coefficient, current, saturation current, and thermal voltage in the fields of the calculator to obtain the result quickly.

Choose a Calculation
Voltage drop(Vd):
Thermal voltage(Vt):
Saturation Current(Is):
Emission coefficient(n):

Steps to Calculate Current Flow through a Diode

The simple step by step process on how to compute the amount of current flowing through a real diode, voltage drop are mentioned here. Follow these guidelines and solve the questions easily

  • Find saturation current, thermal voltage, emission coefficient, and voltage drop of a real diode.
  • Divide the voltage drop by the product of emission coefficient and thermal voltage.
  • Find the exponential of the obtained value and reduce it by 1.
  • Multiply the result by reverse saturation current to check the current flow.

Shockley Diode Equation

The diode is an electronic device that allows the flow of current only in one direction. It takes a p-n junction to allow current flow in one direction. The Shockley diode finds the I-V relationship (Current and Voltage). The Shockley diode equation can be used for both ideal and real (imperfect) diodes. So, it is also called the diode law.

A Shockley diode or PNPN diode has two terminals, three junctions and a four-layer semiconductor device. It is similar to a thyristor with a detached gate.

The Shockley diode equation is

I = Is * ( e(Vd/n*Vt) - 1)


I is the current flowing through the diode

Is is the saturation current which is the intrinsic current in all diodes and is dependant on the temperature

n is the emission coefficient. It is a parametrization of the imperfections of the diode

Vt is the thermal voltage which is the internal voltage in the diode when disconnected from the circuit.

Vd is the voltage drop and is the voltage difference between the connections of the diode to the circuit.


Question: An ideal diode has a saturation current of 15 A, thermal voltage of 150 V and the voltage drop is 120 V. Find the current flowing through the diode using Shockley diode equation?


Given that

Saturation current Is = 15 A

Thermal voltage Vt = 150 V

Emission coefficient for ideal diode n = 1

Voltage drop Vd = 120 V

Shockley diode equation is I = Is * ( e(Vd/n*Vt) - 1)

Substitute the given values

I = 15 x (e120/1 x 150 - 1)

= 15 x (e0.8 - 1)

= 15 x (1.2255 - 1)

= 15 x 0.255

= 18.383

Therefore, the current flowing through ideal diode is 18.383 A.

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Frequently Asked Questions on Shockley Diode Calculator

1. What is a Shockley Diode?

A Shockley diode is 4 layer (p-n-p-n) semiconductor device. It has 4 alternates p-type, n-type semiconductor layers in a single crystal. It was invented by William Bradford Shockley. It conducts when it is forward biased and stops when it is reverse biased.

2. What are the applications of Shockley diode?

The two main applications of Shockley diode are Shockley diode as trigger switch, as a relaxation oscillator.

3. What are the advantages and disadvantages of the Shockley diode?

The advantages of the Shockley diode are it has a high switching speed, and it can do more than a transistor as its construction architecture has two transistors connected with a common terminal. The disadvantage is its construction is very difficult as it involves 4 semiconductor layers.

4. What is the Shockley diode equation?

The Shockley diode equation formula is I = Is * ( exp(Vd/n*Vt) - 1). The parameters of Shockley diode equation is n emission coefficient, I current flowing through the diode, Vd voltage drop, Vt thermal voltage, Is reverse saturation current.