Q.14.10 In a p-n junction diode, the current I can be expressed as
where is called the reverse saturation current,
is the voltage across the diode and is positive for forward bias and negative for reverse bias, and
is the current through the diode,
is the Boltzmann constant
and
is the absolute temperature. If for a given diode
and
then
(d) What will be the current if reverse bias voltage changes from 1 V to 2 V?
As we have
Here, ,
and ,
= Boltzmann constant =
When reverse voltage is 1V, V= -1
When the reverse voltage is -2V:
In both case current is very small and approximately equal to the reverse saturation current, hence their difference is negligible which causes dynamic resistance of infinity.