Q:  Let a silicon diode with n =1.5. Determine the change in voltage if the current change is from 0.1mA to 10mA.

Solution:

                                                                  i = I_s e^v/nVT

                                                            I₁ =Is e ^v1/nVT

                                                             I₂   = I_s e ^v2/nVT

                                                              I₁/I₂ = e^(v1 -v2)nVT

                                                         v₁-v₂ = nV_Tln(I₁/I₂)

                                    Where,               V_T= 25 mV

                                                                 = 1.5 x25 ln( 10/0.1) //put this value in eq

                                                Therefore change in the voltage will be

                                                             v₁ -v₂  =  172.7mV