In this case, the base resistor is returned back to collector as shown in
fig. 2. If temperature increases. β
dc increases. This produces more collectors current. As I
C increases, collector emitter voltage decreases. It means less voltage across R
B and causes a decrease in base current this decreasing I
C, and compensating the effect of
bdc.
Fig. 2
In this circuit, the voltage equation is given by
Circuit is stiff sensitive to changes in β
dc. The advantage is only two resistors are used.
It is better as compared to fixed bias circuit.
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