Question

Why is self bias circuit not used in IC amplifier?

(a) To reduce power losses

(b) To reduce area used on the chip

(c) Stability factor reduces in the IC

(d) Voltage gain is reduced

I got this question in examination.

Question is taken from Transistor Bias Configuration in section Transistor Biasing and Low Frequencies of Analog Circuits

Answer 1

Right option is (b) To reduce area used on the chip

Explanation: Self biased circuits are not preferred in IC amplifiers because they need large resistances R1 and R2, since then S will be smaller and stability will be more. However, using large resistances in ICs means a requirement of larger chip area, so to reduce this area requirement, we use current mirror circuits instead.