Question
Download Solution PDFWhich one of the following is correct regarding stability factor with standard notations?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFStability factor (S):
It is the rate of change of collector current (IC) with respect to the reverse saturation current of collector junction (ICO), i.e.
\(S = \frac{{\partial {I_C}}}{{\partial {I_{CO}}}}\) ---(1)
We know that collector current is given by:
IC = β IB + (1 + β) ICO ---(2)
Differentiating equation (2) w.r.t IC and treating β as constant, we can write:
\(1 = \beta \times \frac{{\partial {I_B}}}{{\partial {I_C}}} + \left( {1 + \beta } \right)\frac{{\partial {I_{CO}}}}{{\partial {I_C}}}\)
\(\frac{{\partial {I_{CO}}}}{{\partial {I_C}}} = \frac{{1 - \beta \frac{{\partial {I_B}}}{{\partial {I_C}}}}}{{1 + \beta }}\)
\(\frac{{\partial {I_C}}}{{\partial {I_{CO}}}} = \frac{{1 + \beta }}{{1 - \beta \frac{{\partial {I_B}}}{{\partial {I_C}}}}}\) ---(3)
From (1) & (3), we get:
Stability factor (S) will be:
\(S = \frac{{\partial {I_C}}}{{\partial {I_{CO}}}} = \frac{{1 + \beta }}{{1 - \beta \frac{{\partial {I_B}}}{{\partial {I_C}}}}}\)
Last updated on Jul 2, 2025
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