The voltage-current characteristic of a diode during forward bias is given by I=7.8 10⁻⁵ e^ 6.5 V_D , where I is the current in mA and V_D is the diode voltage in V . Find the dynamic resistance of the diode in , when the current is 4 ~mA

Step-by-step solution

Differentiating I_D w.r.t. V_D , we get gathered d d V_D (I_D )= d d V_D (7.8 10⁻⁵ e^ 6.9 V_D ) =7.8 10⁻⁵ 6.9 e^ 6.9 V_D =I_D 6.9 gathered Dynamic resistance is d d I_D (V_D ) d V_D d I_D = 1 6.9 I_D When I_D=4 ~mA =4 10⁻³ ~A Then, aligned d V_D d I_D & = 1 6.9 4 10⁻³ & =36.23 aligned Dynamic resistance =36.23