Electrical Engineering ⇒ Topic : Base Bias with Collector Feedback

Base Bias with Collector Feedback

The schematic diagram is shown in Figure (a).

               figure (a) Base bias with collector feedback

                              V_C = V_CC - (I_C + I_B) R_L

                         or V_C = V_CC - I_CR_L    [Neglecting I_BR_L]                ..............(1)

                             V_C = I_BR_B + V_BE                              ............(2)

From Eq. (1) and Eq. (2), it can be obtained as:

                   V_CC - I_CR_L = I_BR_B + V_{BE                  .............. (3)}

Since I_B = I_C/β, Eq. (3) can be written as:

                         ............ (4)

If V_BE is neglected, Eq. (4) becomes

                            ............ (5)

This method provides better bias stability.