Stability Factors

 It is defined as the degree of change in operating point due to variation in temperature. There are three variables which are temperature dependent. Three stability factors are defined as follows,

Stability factor S:

The above equation can be considered as a standard equation for the derivation of stability factors of other biasing circuits.

 Stability factor S^’_:

Stability factor S^’”_:

Relation between S and S”:

 We know that S = 1+β and S” = I_C/β

 Multiplying numerator and denominator by (1+β),

S” = I_C(1+β)/ β(1+β)

S” = I_C S/ β(1+β)